index.md: add tagline metadata

Instead of hard coding the tagline use some metadata
Loading custom rake file from _rake/*.rake
Added error check for git clone system call.
Small fix to check the correct variable (page.comments instead of page.JB.comments) so that disabling comments works as documented.
Issue #46, theme install fails on msys, permissions.
Improved error text.
Added the wordpress_id value in Disqus code if present in the post

Signed-off-by: Tommaso Visconti <tommaso.visconti@gmail.com>
Merge pull request #47 from tommyblue/jb-development

Added the wordpress_id value in Disqus code if present in the post
Adding Mixpanel as analytics provider
Update to bootstrap 2.0.1
Merge pull request #44 from sstarr/patch-1

Resolved an issue preventing disabling comments for individual pages
Setting google as default analytics provider
Merge remote-tracking branch 'nolith/custom-rake' into jb-development. issue #33
Merge pull request #40 from 3martini/windows-topic

Windows MSYS Support
Merge pull request #49 from koomar/jb-development

Mixpanel as Analytics Provider for JB
Merge remote-tracking branch 'daz/master' into jb-development. issue #50
Merge remote-tracking branch 'philips/tagline-metadata' into jb-development. issue #31
bump to 0.2.7
Added option to specify time when creating posts
Using Time.parse to ensure date format is valid