Rearrange source code files

[lufe089]

I'm submitting a...

[ ] Regression (a behavior that used to work and stopped working in a new release)
[ ] Bug report  
[ ] Feature request
[ ] Documentation issue or request
[x] Improvement request
[ ] Support request => Please do not submit support request here

Current behavior

Many current source files are disorganized and do not satify the file structure defined in the developer guides

Expected behavior

Rearrange the source code to satisfy the structure defined in the developer guides