made enabled/disabled checks of apache2_module workable
Fix sync_binlog name in mysql_variables example

The previous sync_binary_log is not a real MySQL variable.
Merge branch 'fixing_apache2_module' of https://github.com/berendt/ansible into berendt-fixing_apache2_module
Merge pull request #7294 from adamchainz/patch-1

Fix sync_binlog name in mysql_variables example
Make sure distro variable is set if python-apt is installed

Fixes #7295
[get_url] check against lowered stripped sha256sum

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
```
Merge pull request #7301 from berendt/check_against_lowered_sha256sum

[get_url] check against lowered stripped sha256sum
Add `upgrade_all` option to homebrew module.