Use pyface undo instead of apptools.undo

[aaronayres35]

fixes #503

As of Pyface 7.2.0, the undo/redo functionality that used to be specific to apptools is now available through pyface. With the upcoming release of apptools, it will be deprecated.

This PR simply replaces all uses of apptools.undo with pyface.undo and updates file names / documentation accordingly.

Note that after this PR, the only use of apptools in the code base will be here:

enable/enable/qt4/base_window.py

Lines 499 to 505 in f83869e

	try:
	# try to extract file info from mimedata
	# XXX this is for compatibility with what wx does
	from apptools.io.api import File
	obj = [File(path=path) for path in files]
	except ImportError:
	warnings.warn("apptools is unavailable", ImportWarning)

Maybe this code could use pathlib instead as mentioned enthought/apptools#143?

apptools is still listed as a dependency in ci/edmtool.py but maybe that can be removed?

Also, note: this PR will cause merge conflicts with #494, but they should be simple enough to resolve (just replace apptools with pyface in the example code that mentions it on 494)

[codecov-io]

Codecov Report

Merging #507 (9a96c32) into master (f83869e) will increase coverage by 0.00%.
The diff coverage is 40.00%.

@@           Coverage Diff           @@
##           master     #507   +/-   ##
=======================================
  Coverage   30.62%   30.63%           
=======================================
  Files         206      208    +2     
  Lines       17830    17832    +2     
  Branches     2454     2454           
=======================================
+ Hits         5461     5463    +2     
  Misses      12036    12036           
  Partials      333      333           

Impacted Files	Coverage Δ
enable/tools/apptools/api.py	0.00% <0.00%> (ø)
enable/tools/pyface/api.py	0.00% <0.00%> (ø)
enable/tools/pyface/move_command_tool.py	86.95% <ø> (ø)
enable/tools/pyface/resize_command_tool.py	85.18% <ø> (ø)
enable/tools/pyface/undo_tool.py	95.23% <ø> (ø)
enable/tools/apptools/__init__.py	100.00% <100.00%> (ø)
enable/tools/pyface/command_tool.py	84.61% <100.00%> (ø)
enable/tools/pyface/commands.py	97.82% <100.00%> (ø)

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[jwiggins]

Concerning the drag and drop handling for Qt... I think some spelunking will be required to see how hard it would be to get rid of apptools (who's using it, what are they doing with the File objects, etc.). Although we're prepping for a major release, so now is probably the best time to "break" it.

[jwiggins]

A question and a comment. This should be good to go once the question is resolved.

[jwiggins]

There was a slight misunderstanding. You should delete everything in enable.tools.apptools except __init__.py and api.py. api.py should forward imports from the new enable.tools.pyface.api module [as well as generating a warning].

[aaronayres35]

There was a slight misunderstanding. You should delete everything in enable.tools.apptools except __init__.py and api.py. api.py should forward imports from the new enable.tools.pyface.api module [as well as generating a warning].

so the warning should be generated from the api or from the __init__.py? when deprecating apptools.undo itself I raised the warning in __init__.py, I'm not exactly sure what is the more correct thing to do

[jwiggins]

__init__.py is probably the better place

[jwiggins]

One comment, otherwise LGTM