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.
don't remove title attribute for tooltips
fixes #6445
Merge pull request #6481 from pseidemann/patch-1

don't remove title attribute for tooltips
Overhaul modal to make it responsive and not super lame
dont remove title attribute part 2
unit tests
Merge pull request #6813 from Yohn/patch-12

don't remove title attribute for tooltips for 2.3-wip
Fixes #6823: add some docs notes about tooltips in input groups
add new modal to docs example
update docs modals
finish modal tweaks
nuke that whitespace
update example code
remove modal test file
fix js from @fat feedback for modal