Move pbldr.py to pbldr/pbldr
Complete refactor

* Split up single file into multiple modules for readability.
* Added yes to all and not to all to existing file overwrite check.
* Pass bash script to bash command on commandline instead of a file.
* Better config handling.
* Better user handling when executing makepkg with root priviledges.
* Better package iteration with Packages() object.
* Removed vim folding markers.
* Improved documentation.