Add template filter functionality

[JakobGM]

It is now possible to:

) Filter which files are considered templates, and therefore should be compiled ) Rename template target names based on regex capture group *) Specify either 'symlink', 'copy', or 'ignore' when handling files that are not considered to be templates

I went with the templates and non_templates config syntax.

Fixes #10.

[coveralls]

Pull Request Test Coverage Report for Build 359

• 616 of 625 (98.56%) changed or added relevant lines in 18 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.2%) to 97.767%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
astrality/module.py	60	61	98.36%
astrality/actions.py	137	145	94.48%
<!--	Total:	616	625	98.56%	-->

Totals
Change from base Build 337:	0.2%
Covered Lines:	3677
Relevant Lines:	3761

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💛 - Coveralls

[JakobGM]

This PR also contains a fix for paths that were considered relative although expanding environment variables made it absolute. Such as $XDG_CONFIG_HOME/something. This has been fixed by expanding env vars before checking if the path is absolute or not.

[JakobGM]

I have now implemented all the features we have discussed above, and think we should merge it into master.

The new actions have been implemented in seperate Action classes, and I am relatively satisfied with that part of the code. But the dispatch of these actions in the form of ModuleManager->Module->(Copy/Symlink/Stow)Action resulted in a lot of duplicate application and test code.

It should probably be refactored at some point, perhaps by using getattr a lot more, instead of defining seperate symlink/copy/stow/... methods on both Module and ModuleManager. That way we could delete a lot of duplicate code.

But for now it should suffice, I am tired of this issue :persevere: