clean-up: fix PEP8 E111 indentation is not a multiple of four

clean-up: fix PEP8 E701 multiple statements on one line (colon)

clean-up: fix PEP8 E741 ambiguous variable name

clean-up: fix most PEP8 E221 multiple spaces before operator

clean-up: fix most PEP8 E266 too many leading '#' for block comment

clean-up: fix PEP8 E703 statement ends with a semicolon

clean-up: fix PEP8 E301 expected 1 blank line, found 0

clean-up: fix PEP8 E306 expected 1 blank line before a nested definition, found X

clean-up: fix PEP8 E305 expected 2 blank lines after class or function definition

clean-up: fix PEP8 W391 blank line at end of file

clean-up: fix PEP8 E201 whitespace after '{'

clean-up: fix PEP8 E202 whitespace before ')'

clean-up: fix PEP8 E227 missing whitespace around bitwise or shift operator

clean-up: fix PEP8 E251 unexpected spaces around keyword / parameter equals

clean-up: fix PEP8 E711 comparison to None should be 'if cond is not None:'

clean-up: fix PEP8 E225 missing whitespace around operator

clean-up: fix PEP8 E303 too many blank lines

clean-up: fix PEP8 E231 missing whitespace after ':' or ','

clean-up: fix PEP8 E203 whitespace before ':' and whitespace before ','

clean-up: fix PEP8 E271 multiple spaces after keyword

clean-up: fix PEP8 E261 at least two spaces before inline comment

clean-up: fix PEP8 E302 expected 2 blank lines, found 1

clean-up: fix PEP8 W293 blank line contains whitespace

clean-up: fix some PEP8 E228 missing whitespace around modulo operator

clean-up: fix some PEP8 E265 block comment should start with '# '

clean-up: fix PEP8 E401 multiple imports on one line

convert some files from CRLF to LF

It'll break for these files hg blame/annotate. Fortunately not many
files are affected.

clean-up for PEP8: fix W291 trailing whitespace

README.md edited online with Bitbucket

fix link to documentation in README.md