Add Validation and rspec tests for $error_log

Without this commit, there is no validation or testing for the
$error_log parameter in the apache::vhost type.

This commit add boolean validation to the apache::vhost type. It also
adds two rspec tests to test the proper function of the parameter.
Merge pull request #186 from trlinkin/refactor_vhost_logformat

Add Validation and rspec tests for $error_log
trying to test some of the passenger parameters
testing that the passenger.conf contains passenger and ruby root directories, and no other declarations.

...there is possibly a better way of doing this...
simplified regex....
Fix Red Hat ruby root. Remove tests for things that should be missing.
starting testing parameters
This should provide a complete set of parameter tests.
only _one_ typo in that last lot O_o
described the aliases parameter, but does nothing yet
Describe the directories parameter
This should put the aliases in a list after DocumentRoot, provided that .erb can handle hash["key"]
missing hash rocket  => in examples
create a template fragment for directories

...again I hope .erb hash processing works...
oops, missed a refactor.
missed refactor to directory
First character uppercase is not good for hash keys
ug, wacky repeating typos.
apache::mod::php needs a custom lib for Debian and Ubuntu
ah, php is not compatible with apache::mod::worker, and requires apache::mod::prefork