Create a sectioned move to dialog for folders.

Part 1: make it possible to have section headers and sections
that consist of folder adapters.
1) for system
2) for frequently used
3) for all

right now, just repeats the same full folder adapter for all.
The next CL will make 3 diff FolderSelectorAdapter subclasses:
1) system only (added to this cl)
2) frequently (and hierarchical)
3) all (and hierarchical)
Change-Id: I7cceb35a6940180461d75186e8430a2340da2222
6 files changed