Remove fuelweb from repos path

Should be synchronized with appropriate patchsets in fuel-web and
fuel-main.

Change-Id: I93d2b735b7c372a934df09edcb59faafa96c92e0
Related-Bug: #1377160
Prepare build environment

1. In case Ubuntu 14.04:
- add devops repository and install multistrap version 2.1.6
- Pin multistrap version 2.1.6
2. In case Ubuntu 12.04:
- add chris-lea (for nodejs) repository with higher priority
- install nodejs from chris-lea repository
3. For all distributions
- fixed npm global installation permission issue
- ensure bc package is present for make img target

Closes-Bug: #1337343
Closes-Bug: #1312654
Change-Id: I62ba9257fb3d575d996bf4c57b5d983c0050fd3b
Set permissions on nailgun files installed

Includes a workaround in nginx start.sh script to
reset permissions on /usr/share/nailgun/static
because Docker resets it to 700.

Change-Id: I9172a888cd72ded9ce16897b1e779d994b9802e7
Closes-Bug: #1380950
Merge "Prepare build environment"
Merge "Remove fuelweb from repos path"