avoid crash when colorspace is null.
imagewriter now works with text output
fixed: invalid bmp file output
experimental layout analysis improvements
Optimize group_textboxes function.
Merge remote-tracking branch 'upstream/master'
Use set instead of list for Plane's internal collection of objects.
Optimize group_textboxes function.
Merge jcushman/pdfminer optimizations

because they are very helpful
dumppdf: support for extracting embedded files using the -E option
Merge remote-tracking branch 'dangra/master'
Merge remote-tracking branch 'jcushman/patch-2'
Merge remote-tracking branch 'jcushman/patch-1'
resolve all attributes on a page
simplify `isinstance()` check
correct PNG parsing
version bump
Merge remote-tracking branch 'matchbox/master'

Conflicts:
	pdfminer/layout.py
bump version number
readd cmap to setup (run `make cmap` first)

cmap dir is created with make. run this first before setup.py to avoid
issues.