Merge pull request #188 from igniteflow/master

Add export options to help message
Dynamically load 3L library
Require config arguments
Use PyXDG to save config and journal in XDG dirs

This change also hides the CONFIG_PATH state information entirely within
the install module. Therefore, the cli module does not have to care about
checking existence of files and paths.
Allow parallel edits

* Wait to open the journal until after getting text
* Use mktemp so that editors like vim get separate files for editing
Allow 'text' and 'markdown' aliases in export to dir

Fixes #201
Fixes error when exporting txt files

Fixes #202
Merge pull request #204 from chrissexton/parallel_edits

Allow parallel edits
Merge pull request #206 from matze/integrate-pyxdg

Integrate pyxdg
Version bump
Export to xml
Better unicode mock support
Fixes unicode errors in XML export
Cleans up entry
Docs
Merge branch 'pr/211' into 2.0-rc1
Make Journal a general interface

This change moves the loading and saving mechanisms into its own
Plain- and EncryptedJournal subclasses for easier maintenance and lazy loading
of all the crypto modules.
Move and remove imports in utils
Remove circular dependency