Splits the progress @echo statements in the Makefile.
Replaces some @echo recipes by @printf.

The echo command does not understand the -n argument on Mac OS X.
This is due to the fact that:

  - Makefile calls /bin/sh to execute a command
  - in Mac OS X, /bin/sh is a link to bash
  - in Mac OS X, bash is compiled with --enable-strict-posix-default

Therefore, the echo command does not have the -n argument.

printf on the other hand is a builtin function that works well on Mac OS X and Linux.
Moves one @printf statement to be more accurate.
Modifies the Makefile to use local npm install **when available**

The change introduced in 5bd8cdca9 was:

  - partial, as not all the command were translated
  - preventing the use of a global npm installation
Allows the user to set different source and destination in Makefile.

A user can use the following command to determine where to copy the resulting css file:

    $ BOOTSTRAP=<my-path> make
Changes some more commands to use the local npm install.
Added retina image support mixin
nuke dat extend docs page
convert to jekyll
nuke what we don't need for jekyll
update makefile to work given nuked docs dir
rearrange jekyll and docs
Merge branch '3.0.0-wip' of github.com:twitter/bootstrap into 3.0.0-wip
Restore gallery page, add active nav class jankitude, auto regenerate docs on file save
update makefile to work again; gitignore the compiled docs _gh_pages folder; test makefile with darkened navbar active bg
make same css docs fix from upstream
update readme to reflect jekyll docs and local npm install method
readme improvements
update readme to point to getting started page; twerk link
Start using some includes; test out some pygments highlighting