Installer: Checkbox to remove rocks directory on uninstall

[RussellHaley]

No description provided.

[RussellHaley]

One of the components of WinLua is the LuaRocks package manager. LuaRocks adds Lua modules called rocks that consist of binaries and text files and are installed in the lib directory with a version of Lua (lib, bin, static, include). These files should optionally be cleaned up by an uninstall step. It is advisable to have a check box in the uninstall sequence. The message should be: "Remove LuaRocks System RockTree? Select this to remove all files from your computer."