Added new block IDs

- carpet, hay, hardened clay, coal block IDs added
Added Stained Clay block ID
Fixed ChangeLog typo
Allow case insensitive matching for minecraft.jar
Merge pull request #160 from GunfighterJ/master

Allow case-insensitive matching for minecraft.jar
Refactored texture pack loading

- indexed textures are now handled as alternate textures
Use log4j.logLevel system property for log level
Added documentation comment
Refactored Minecraft install finding code
Support new Minecraft launcher

- find Minecraft jars by latest version in the versions directory
Added hay block
Added rendering of hardened clay block
MC 1.6.1 texture paths

- updated texture paths to support Minecraft 1.6.1
- supports "resource pacs" and fixes #158
Implemented carpet rendering

- render Minecraft 1.6 carpet blocks
Implemented stained clay rendering
Implemented coal block rendering

- render Minecraft 1.6 coal blocks
- fixes #159
Updated ChangeLog
Added license info for Gson

fixes #163
Updated ChangeLog
Updated build script

Added gson to build classpath.