parallel.apps.ipcontrollerapp: Use utils.localinterfaces

... for LOCALHOST and PUBLIC_IPS, rather than duplicating the socket
incantation and hard-coding 127.0.0.1.
frontend.html.notebook: Use utils.localinterfaces.LOCALHOST
parallel.util: Use utils.localinterfaces

... for LOCALHOST and PUBLIC_IPS.
parallel: Use utils.localinterfaces.LOCALHOST
add version comparison utility
    
all version strings are comparable by casting string elements to float('inf')
use NumericalVersion utility in external.qt
start introducing less
start to migrate to variables
start mixins
Revert "remove less.css"

This reverts commit 076a0fac5a12d4b674f2343f484a2c983a410219.
use less for tooltip
remove useless classes
main_app -> ipython-main-app
add less flag
generate style.css
less flag in templates
fix print css less
make file and other less
readd flexible-box-model
Add and remove boostra squashed commit

To reduce branch size as bootstrap is huge

add default bootstrap theme
does not import code in bootstrap
remove bootstrap