adding test for pie ccw. Also removing pdf and svg files from pie linewidth tests
#2897 changing comment for the pie clockwise test
adding changelog entry
#2150 wip - added change log
#2897 removing ccw=false test
Merge pull request #2933 from sfroid/issue_2897

closes #2897 Adding tests for pie ccw. Issue 2897
BUG: Fixed bug in handling drawing bitmap images accounting for the device scaling
'an' -> 'and'
Replace a no longer working link with a description of its content

The link can still be accessed through the Internet Archive at
http://liveweb.archive.org/web/20100831121909/http://sourceforge.net/tracker/index.php?func=detail&aid=1962574&group_id=80706&atid=560720
but its content can be summarized in one sentence.
Merge pull request #2940 from mineo/doc-fixes

Fix some documentation mistakes
#2150 updating comments
remove .rect member (clashes with QWidget)

FigureCanvasQTAgg inherits from QWidget, which already has a 'rect'
property and getter.

Also, consolidate .rect and (boolean) .drawRect into a single _drawRect
member.  This is only used for the zoom rect and not accessed from other
classes (other than indirectly via the drawRectangle() function).
Re-Generate legend, through apply_callback/Apply

If there is a legend, it is re-generated when "Apply" is clicked.
See Issue #2934:
Might have side effects.
matplotlib#2934
tacaswell: "However this will clobber any legend that is not the auto-magically generated one so it should probably also get a tick box to enable/disable the updating of the legend."
Tick box not included.
update api_changes.rst w.r.t. Qt4 backend changes
explicitly test _drawRect against None
DOC : added missing doc changes from #2844
CLN : removed version check that required numpy > 1.2
Merge pull request #2848 from tacaswell/windows_install_doc

DOC : removed line about un-needed dependencies in Windows
Merge pull request #2949 from tacaswell/np_version_purge

CLN : removed version check that required numpy > 1.2
Merge pull request #2939 from cimarronm/macosx_device_scale

Fixes a bug in drawing bitmap images in the macosx backend for handling device scaling