diff --git a/.idea/codeStyles/Project.xml b/.idea/codeStyles/Project.xml
index 6467f2538..1a51cfcd7 100644
--- a/.idea/codeStyles/Project.xml
+++ b/.idea/codeStyles/Project.xml
@@ -52,25 +52,6 @@
       <option name="SPACE_BEFORE_SUPERCLASS_COLON" value="false" />
     </Objective-C>
     <Objective-C-extensions>
-      <file>
-        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Import" />
-        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Macro" />
-        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Typedef" />
-        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Enum" />
-        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Constant" />
-        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Global" />
-        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Struct" />
-        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="FunctionPredecl" />
-        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Function" />
-      </file>
-      <class>
-        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Property" />
-        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Synthesize" />
-        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="InitMethod" />
-        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="StaticMethod" />
-        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="InstanceMethod" />
-        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="DeallocMethod" />
-      </class>
       <extensions>
         <pair source="cc" header="h" fileNamingConvention="NONE" />
         <pair source="c" header="h" fileNamingConvention="NONE" />
diff --git a/build.gradle b/build.gradle
index 73fa65dfc..e26d24fb5 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,7 +1,7 @@
 apply plugin: "com.github.ben-manes.versions"
 
 wrapper {
-    gradleVersion = "4.10.1"
+    gradleVersion = "5.1.1"
     distributionType = Wrapper.DistributionType.ALL
 }
 
@@ -15,7 +15,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.3.2'
+        classpath 'com.android.tools.build:gradle:3.4.0'
         classpath 'com.google.gms:google-services:4.2.0'
         // https://docs.fabric.io/android/changelog.html#fabric-gradle-plugin
         classpath 'io.fabric.tools:gradle:1.27.1'
diff --git a/dav4android b/dav4android
index c8ddef19a..d7c8d849c 160000
--- a/dav4android
+++ b/dav4android
@@ -1 +1 @@
-Subproject commit c8ddef19a0e25791691795e3702b7684fdae41f4
+Subproject commit d7c8d849c0a2b75387e5acdfe488e8392b4037b6
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 135367700..87b738cbd 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 93d9a09ad..53a2d1cb7 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Tue Feb 05 11:11:15 CST 2019
+#Wed Apr 17 16:00:31 CDT 2019
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.1.1-all.zip
diff --git a/gradlew b/gradlew
index cccdd3d51..af6708ff2 100755
--- a/gradlew
+++ b/gradlew
@@ -28,7 +28,7 @@ APP_NAME="Gradle"
 APP_BASE_NAME=`basename "$0"`
 
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS=""
+DEFAULT_JVM_OPTS='"-Xmx64m"'
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD="maximum"
diff --git a/gradlew.bat b/gradlew.bat
index e95643d6a..0f8d5937c 100644
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -14,7 +14,7 @@ set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
 @rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-set DEFAULT_JVM_OPTS=
+set DEFAULT_JVM_OPTS="-Xmx64m"
 
 @rem Find java.exe
 if defined JAVA_HOME goto findJavaFromJavaHome
diff --git a/ical4android b/ical4android
index a49c1418f..9648d42cf 160000
--- a/ical4android
+++ b/ical4android
@@ -1 +1 @@
-Subproject commit a49c1418f7c49ef04c9c4b90c292990045476452
+Subproject commit 9648d42cf6257ca1fb46aa8f43eb9f29380acd1d