Introduced build files from the tmr git repository
Updated .gitignore to ignore the make cache

Also merged with the Windows.gitignore and the VisualStudio.gitignore
files from the github/gitignore repository.
Added excmd module.
Added empty README
Removed @excmd directory

Restructured directory to conform with the layout of the tmr source tree.
This addon is now using the build system from the tmr addon.