Add mr's vcsh lib to docs

* Make include more resilient (Thanks to Thomas Koch)
* Fix emphasis issues with underscores in variable names in MarkDown

Thanks to Brain May for pointing this out.

fixes #22

Thanks to Brian May for reporting this.

fix #22

Add hooks for setup()

* Fix and expand manpage
* Use explicit variable names in hook()

Thanks to Vincent Demeester for this idea.

One to go and that may just move to github issues...

Thanks to David Bremner for reporting this

* Refer to README.md
* Add note about config file being a potential security issue

* configuration is in $XDG_CONFIG_HOME/vcsh/config
* $VCSH_GITIGNORE can be set to 'exact' or 'recursive'

People arriving via http://onethingwell.org/post/14218384411/vcsh
should be able to find us..

1.7.7 is happy without parameters, 1.7.0.8 needs origin master