Add erase manager, originally from storaged

:Release Notes:
Since the presence of storaged cannot be guarenteed, the erase
functionality has been copied here, and modified for C++.
LunaSysService now supports an 'erase' category to support the
following commands: "EraseAll", "EraseMedia", "EraseVar" and "Wipe",
plus the new command "EraseDeveloper".

:Detailed Notes:
New private methods:
- com.palm.systemservice/erase/EraseAll
- com.palm.systemservice/erase/EraseDeveloper
- com.palm.systemservice/erase/EraseMedia
- com.palm.systemservice/erase/EraseVar
- com.palm.systemservice/erase/Wipe

:Testing Performed:

:QA Notes:

:Issues Addressed:
[GF-39468] Provide factory reset message implementation

Change-Id: Iead042283c8662965dc32bebf17912623e6fd2ec
Open-webOS-DCO-1.0-Signed-off-by: Roger Stringer <roger.stringer@lge.com>
Reviewed-on: https://g2g.palm.com/3535
Reviewed-by: Build Verification
Reviewed-by: Keith Derrick <keith.derrick@lge.com>
Tested-by: Keith Derrick <keith.derrick@lge.com>
Reviewed-by: Roger Stringer <roger.stringer@lge.com>