Release version 2.1.0

Changes
CAPI : error code added (CSR_ERROR_USER_RESPONSE_FAILED)
thread pool to static
thread-safe of cynara
thread-safe of db module
handle more events on popup (rotate, home button...)
handle preloaded app in file-unit (not abstracted by package level)
handle history of detected malware by scan on cloud (db schema changed)

Change-Id: I97d9e55c4e7a0bae55f53af20963497e46aa0358
Signed-off-by: Kyungwook Tak <k.tak@samsung.com>