Merge branch 'upstream' into strike-extension
add instructions for strike-through extension
Do not print "\usepackage{}" line

The generated LaTeX output is understood to be the document body,
so it may not contain macros that belong into the preamble.
Merge pull request #12 from rekado/strike-extension

New extension: strike through with two tildes
Merge remote-tracking branch 'upstream/master'

Conflicts:
	README.markdown