Merge pull request #3 from FCP-INDI/0.3.4_development

0.3.4 development
Changed the version number from 0.3.3 to 0.3.4.
Widened the 'Create FSL Model' button so that the whole button label
would be visible.
Implemented the basic checkbox grid GUI interface for the group analysis
model builder. More work is needed to fully integrate it further.
Creation of the checkbox_grid wxPython widget for the renovated group
analysis model builder.
Merge branch 'new_gpa_model_builder'

Conflicts:
	CPAC/__init__.py
	CPAC/pipeline/cpac_pipeline.py
Resolved three GUI-based errors which previously obfuscated user experience (two involving pipeline creation errors and one involving pipeline name conflicts), and wrote new documentation for some of the legacy GUI code.