Status bar: Add HSPA+ icons

Forward port H+ icon in the status bar when connected to HSPA+
Uses new vector drawables by @blunden

PS1: Initial commit
PS2: New vectors (thanks @blunden)
PS3: Cleanup
PS4: Use correct indentation (oops)
PS5: Show correct icon in status bar (thanks @mikeNG)
PS6: Remove leftover Holo icons (thanks @mikeNG)
PS7: Rebase to depend on Holo icon removal (thanks @mikeNG)
PS8: Update commit message

Change-Id: Ia745c524d5e2530f50f12f961ea8533a4c8f5842
Don't know why slim_strings was in the mix
SystemUI: fix H+ data icon showing when wifi is connected