Thanks to _that, return null if vector is empty

Change-Id: Idc44455dd0c971c876ae283528c4367a82e145bd
Clean up make flash utility make files

Change-Id: Ie396be7d9636a8b481bcf7c062f94ce51a4b1fde
Make libmincrypttwrp a shared library

Change-Id: I8c3f084fc34b00edb4cd1b652290df8bc80ea1db
Tweak 5.0 L decrypt

Mount the vendor partition if it exists so we can use any
proprietary files we may need.
Relocate auto decrypt when default_password is in use to after all
partitions are added so that we can mount the vendor partition.

Change-Id: I93455a35695779f53ef57a82d3d45c7216c13639
Add flag for including additional files built from source in TWRP

Some devices may need additional binaries or libs that TWRP
normally does not need included in /sbin
Use TW_RECOVERY_ADDITIONAL_RELINK_FILES to build them from source
and get them added to the recovery ramdisk.
For example, Nexus 9 needs libc++ included in order to decrypt
the data partition. The following will build it from source and
include it in TWRP:
TARGET_RECOVERY_DEVICE_MODULES := libc++
TW_RECOVERY_ADDITIONAL_RELINK_FILES := \
    out/target/product/volantis/system/lib/libc++.so

Change-Id: I147c0d5569c83514d2e50226ecc50e80bf8aac36