Merge pull request #142 from enthought/fix/travis-kiwi-build

Use pip to install kiwi now that it has a proper build script
Add base tool to facilitate drag and drop support.
Example of use, plus re-work based on actually using the code...
Rename drop_tool base_drop_tool
Rename drop tool to base drop tool.
Add test support for drop tools.
Fix send_key.
Minor fixes.
Add some documentation around drag and drop.
Merge pull request #143 from enthought/feature/drop-tool

Drop Tool
Remove commented methods from the PDF and Base graphics contexts
Remove some commented code from the font manager.
Merge pull request #147 from enthought/cleanup/kiva-commented-code

Last of the commented code removal
Merge pull request #139 from enthought/feature/abstract-graphics-context

Partial Kiva code clean-up
Merge branch 'master' into template-test-case-for-graphic-contexts
always clear the graphics context
Merge remote-tracking branch 'origin/template-test-case-for-graphic-contexts' into template-test-case-for-graphic-contexts

Conflicts:
	kiva/tests/drawing_tester.py
minor cleanup