Missing quotation marks around div id.
Adde custom string for Mac OS X Mavericks in Systen::getKernelRelease().
Fix for bug #185.
Some code cleaning.
Merge branch 'devel' of github.com:aarpon/hrm into devel

Conflicts:
	home.php
Bug fix in User::password().
Implemented feature #119.
Implemented feature #174 and cleaned the code a bit.
Added method to the Parameter class to allow serialization for JSON encoding. PHP 5.4 supports it out of the box, but this approach works also for older PHP versions. Extended json-rpc-server.php accordingly.
Added method to json-rpc-server.php to retrieve all image parameters as a JSON-enconded array.