Revert "Remove the cbs creation for n900 plugin, this lead to crashes on n9 ofono init."

This reverts commit 804bef98ad3ddef0af8d28d3d46a1f3d85a8b002.
Fix cbs related n900/isimodem crash

Don't remove cbs data during shutdown sequence in isimodem driver, since
it is already being removed.

[n900] Fix cbs related crash
[packaging] Fix error in changelog date format preventing mb2 builds
Merge pull request #268 from hedayat/master

Re-enable CBS in n900 plugin and fix CBS related crash in N9