Increased version and add chnagelog for 0.15.2

Ignore-this: 1ce69d8d9ba3f6d88c0c71607e02a99a

darcs-hash:20100727160928-58252-51e92f30dc2dc139a699a2549a8f0ce32f31d9ab
Fixed spelling

Ignore-this: c5e2bdb2abc0d4ce395e7a2dd6570b98

darcs-hash:20100727210939-b22ec-99f8c41f3373bfafcfacefa7674821b6141c00dd