Fixed parsing of 'time' in front of compound commands
Parser: accept here doc token strings more liberally
If printf string contains %, don't warn about using vars
Don't warn about single quoted vars for ssh
Warn about 'foo=bar echo $foo'
Fixed parser error for '..; done| ..'
Added a shellcheck(1) man page

The manual is mainly a copy/paste from the current documentation. It is
builded with pandoc, and written in markdown.

closes #50
Warn about 'i=i+1' and 'i=i + 1'
Minor performance tweaks (~10% improvement)
Merge branch 'man_page' of https://github.com/Dridi/shellcheck into manpage
Tweaked man page format
Merge branch 'manpage'
Parser: allow subshell function definitions
Fixed ${!var} not counting as reference of var