GitLab

Squashed commit that allows MultiROM TWRP to be built from
within the standard TWRP environment.

MultiROM build flags and TARGET_RECOVERY_IS_MULTIROM
must be defined in device tree.

-------------------------------------

MultiROM-support:
- Move files to separate folder
  * Move primary multirom files to /recovery/multirom
  * Move multirom prebuilt files to /recovery/multirom/prebuilt
  * Move cp_xattrs folder used by multirom to /recovery/multirom/cp_xattrs
- Add Android.mk for mrom-prebuilt files
- Add Android.mk for mrom-cp_xattrs files
- Fix include paths
  * fix includes in multirom.h/c/hpp/cpp files to go to parent (main recovery folder)
- Add read_data function
  * Add read_data function used by multirom
  * Don't append to minzip, use a seperate file
- Remove deprecated 'flags' variable
  * Remove deprecated 'flags' in function call to mzExtractRecursive
  * Ref: https://github.com/omnirom/android_bootable_recovery/commit/9c0f5d6b348e37533bdcccf1166d6cbf1ca5c50b
- gui: Add multirom functions
  * objects.hpp - Add multirom action definitions
  * action.cpp - Add multirom actions and functions
    Note: TW_ORS_IS_SECONDARY_ROM code moved to openrecoveryscript.cpp
  * Add TARGET_RECOVERY_IS_MULTIROM flag to Android.mk
  * Reorder code changes for easier merging
- twrp-functions
  * Add functions needed by multirom
  * Reorder code changes for easier merging
- partition.cpp and partitionmanager.cpp
  * Add and embed multirom specific code
  * Reorder code changes for easier merging
- twrp.cpp
  * Add and embed multirom specific code
- variables.h
  * Add multirom specific defines
- Android.mk
  * update Android.mk for compartmentalized multirom
- gui: Update fileselector
  * Add <excludes> tag
  * Add support for multiple file extensions
- gui: Update listbox
  * Add support for dynamic <items> tag

Thanks @CaptainThrowback and @z31s1g for your help