project_builder.py: implemented basic functionality for building projects (fix #1)
dialogs.py, wizard.py PEP8 errors fixed
Merge pull request #30 from boyks/master

dialogs.py, wizard.py PEP8 errors fixed
implemented source_loader (fix #3)
implemented spec (fix #4)
assigned components together
2-5,7 pages' validations
removed __init__ from ProjectBuilder
Merge branch 'upstream'
Dialog for adding subpackage added

Added buttons to subpackage dialog

Tags and scripts validations

Filter for file browser (user can choose only dir)

Also there is an output to the stdout for checking scripts and tags