broken but adding pyana
Merge remote-tracking branch 'rhewett/namespace_cleanup' into sun_ana

Conflicts:
	sunpy/io/__init__.py
Made ANA work again, not sure if the style is the same as the new name space
methods.
Minor change, to get import sunpy.io.ana to show
Minor Change
Started the clean up of documentation for ana.
Merge remote-tracking branch 'upstream/staging' into sun_ana
Who knows? Time to doc this shit up.
Merge branch 'staging' of github.com:sunpy/sunpy into sun_ana
added tables.py, contains tables defined via SQLAlchemy
added class CommandManager which acts as an undo-redo-manager and the command classes AddEntry, EditEntry, RemoveEntry
added the main database interface, the Database class
added database/__init__.py
added caching support. builtin supported caching strategies are LRU and LFU
Merge branch 'staging' of https://github.com/sunpy/sunpy into database
clear the redo stack after a new command has been executed
fixed typos in seealso references
support undoing adding an entry even if this add command has not been commited
added __contains__ method to Database class so that one can easily check if an entry exists
use a pytest fixture for the CommandManager related tests