bootstrap 2 as 'bootstrap2.3.2' in bower dependencies

This is the name it is distributed in bower,
and will not clash with 'bootstrap' if someone needs bootstrap 3.
Using 'bootstrap2.3.2' amd symbolic path

... without the deprecated 'amber_lib'
formatting
jQuery dependency changed to >=1.7.0

to not clash with project that need jQuery 2.
1.7.0 selected so that .on and .off are present.
Otherwise AFAICT Amber does not use any new jQuery features,
but feel free to put higher number there if needed.
jQuery UI dependency changed to >=1.9.2

Again, to clash less with the actual projects
Merge pull request #1023 from herby/bootstrap2-legacy-name

Bootstrap2 legacy name