The content of the sha256sum attribute should be lowered before comparing it with the calculated sha256sum.
In the following example the used sha256sum uses ABC.. and not abc.. and the check failed. This should not happen.
```
TASK: [get_url url=http://ftp.fau.de/apache/hadoop/common/hadoop-2.4.0/hadoop-2.4.0.tar.gz dest=/home/vagrant/hadoop-2.4.0.tar.gz mode=0644 sha256sum=024326AC68A1A68B5566B10F95609EAAFD9F70CFEB37FCA0E97CBB1674E57C3A] ***
failed: [instance000] => {"failed": true}
msg: The SHA-256 checksum for /home/vagrant/hadoop-2.4.0.tar.gz did not match 024326AC68A1A68B5566B10F95609EAAFD9F70CFEB37FCA0E97CBB1674E57C3A; it was 024326ac68a1a68b5566b10f95609eaafd9f70cfeb37fca0e97cbb1674e57c3a.
FATAL: all hosts have already failed -- aborting
```
* the current state of the ELB was not reflected properly when checking
the status after a change was made.
* invalid zones caused a traceback when enabling/disabling zones
ec2_snapshot got missed when moving to a common argument spec.
It could already make use of the capabilities (as it uses
ec2_connect) and the documentation suggested it supported the
common argument spec (thanks to the documentation fragment work)
so it was just a matter of fixing the argument spec.
Removed unnecessary documentation for profile and security_token
that is covered by documentation fragment
Also removed spurious documentation flags (default: null, aliases: [])
which aren't needed.
If we try to use the user module without being root, it fail on RHEL/Fedora
because usermod --help cannot be run. The root cause is lack of permission
due to EAL4+ certification, as seen in shadow-utils changelo.
So if we cannot run it, assume there is no append. It doesn't matter
much since we will not be able to run usermod at all with or without the
option.
The current 10-second default timeout for rsync seems to be behind issue #6809.
As a workaround for the underlying issue in rsync when different versions are
used on the source and destination sides, don't include the timeout option
unless the user specifies a timeout > 0.