Make TWRP compile for arm64

-Remove dosfstools for arm64 until we can make it compile
-Fix TW_USE_TOOLBOX flag to work again
-Fix symlinking and handling of sh when using mksh
-Fix legacy properties to find futex_wake function
-Fix libcrecovery to not use bsd_signal anymore
-Fix rules for building with regards to libcrecovery
-Update toolbox_recovery rules to compile tools in lollipop
-Fix a few compile errors specific to arm64

Testers report that TWRP does not boot on Nexus 9 and we fail to
get a shell for adb shell. At least it compiles without errors.

Change-Id: I286be8628defb60cc527b8a548c0bdfcb0ebb574
diff --git a/flashutils/Android.mk b/flashutils/Android.mk
index 3209cb0..a697a09 100644
--- a/flashutils/Android.mk
+++ b/flashutils/Android.mk
@@ -83,7 +83,7 @@
 LOCAL_MODULE := libflashutils
 LOCAL_MODULE_TAGS := eng
 LOCAL_C_INCLUDES += $(commands_recovery_local_path)
-LOCAL_SHARED_LIBRARIES := libc libmmcutils libbmlutils
+LOCAL_SHARED_LIBRARIES := libc libmmcutils libbmlutils libcrecovery
 LOCAL_STATIC_LIBRARIES := libmtdutils
 
 BOARD_RECOVERY_DEFINES := BOARD_BML_BOOT BOARD_BML_RECOVERY