CMFM: CYAN-285 - Add ability to calculate file checksums

Added support for compute MD5 and SHA1 file checksums

Patchset 2: Remove trailing whitespaces

Change-Id: I46cbd0d451eea76e259bdddc485774bbfd34cdc0
JIRA: https://jira.cyanogenmod.org/browse/CYAN-285
Bugfix: CYAN-285
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>