Add Doxygen builder to site_scons
Clean up files

- Remove trailing whitespace.
- Use `rising_edge` instead of `sig'event and sig = '0';` pattern.
- Made TBs produced by tbgen compilable.
Merge pull request #18 from willprice/develop

Develop
Merge pull request #19 from willprice/master

Merge pull request #18 from willprice/develop
Rename arch_rtl in template
Update templates
Merge branch 'develop' of github.com:willprice/vhdl-computer into develop
Update templates
Massive refactor of tbgen.py
Merge branch 'develop' into feature/modules