Check if jenkins_home/plugins exists

The code was raising an exception if ~jenkins
existed, but ~jenkins/plugins didn't. Change
the code to check for plugins from jenkins_home.
@ all variables and some empty character removal
Missed two variables
Merge pull request #72 from mrchilds/template_variable

@ all variables to avoid deprecation warnings
Creting home directory for jenkins user
manifests/init.pp: fixed typo in comment.

s/installl/install/ and some minor improvements.
Merge pull request #75 from php-coder/patch-1

manifests/init.pp: fixed typo in comment.
Fix for #74 - 'Invalid relationship' when installing plugin
Merge pull request #76 from jchristi/master

Fix for #74 - 'Invalid relationship' when installing plugin
Updating user home to use default JENKINS_HOME of /var/lib/jenkins instead of /home/jenkins
Merge pull request #73 from dtsato/master

Creating home directory for jenkins user
fix travis ruby 1.8.7 issues
add puppet 3.3, 3.4, remove 3.0 for rspec >= 1
Merge pull request #79 from jlambert121/ruby187

fix travis ruby 1.8.7 issues
lint fix
Add note about plugin dependencies to README.markdown
Merge remote-tracking branch 'upstream/master'
Merge pull request #83 from jchristi/master

Add note about plugin dependencies to README.markdown
Merge pull request #82 from dcrissman/dev

Lint Fix
Merge pull request #68 from ambakshi/fix-jenkins-plugins-facter

Check if jenkins_home/plugins exists