Allow missing color, style or image properties for a given skin.
Fixes warnings about unused imports and unnecessary casts.
Clarify the use of a field to Eclipse on Mac OS X with Java 5.
Fix some javadoc warnings, typos and 80 lines cut.
Added the possibility to have the skin main directory in the skin zip.
Patch provided by Adam Netocny, icluding some skin jar builder enhancements + javadocs.
Support for video and photo previews in chat window provided by Purvesh Sahoo as part of its GSoC project.