Support PKCS#12 cert stores in PharPackageTask.

Allow a PKCS#12 certicate store to be used instead of a regular PEM-encoded
private key in the <pharpackage> task.
Usage is similar to that of private keys, with the "keypassword" attribute
being used as the store's passphrase.
Added som documentation for customization of the DocBook5. Minor cleanup of DocBook5 stylesheets + some spelling fixes.
Added README for CSS directory
Merge pull request #231 from omnicolor/master

Added missing attribute to UpToDateTask documentation
Merge pull request #229 from fpoirotte/pkcs12

Support PKCS#12 cert stores in PharPackageTask.
Merge pull request #230 from johan162/master

Updated documentation for DocBook5
Add additional phpunit configuration (disables backupGlobals etc)
Add missing attributes for pharpackage task
Update output targets
Don't install xdebug
Fixes #1037 - close filterchain element
Fixes #1036 - use command variable for passthru() call
added PhpStorm License info
Merge pull request #232 from bschultz/master

Added PhpStorm License info to README
Slight wording change
Add contact section
Update changelog for next release
Update deps
Update output targets
Remove cache dirs