Use base-10 for partition sizes
Shorten recovery name
Update to 15.1.C.2.8 stock ramdisk
Let recovery handles mount (busybox)
Fix misleading comment in combinedroot init script
Update prebuilt kernel with kexec-hardboot

See https://github.com/alvinhochun/sony-xperia-m-kernel/commit/2e818d81f21f6a627bc629e477052045426b0663
Recovery: Use custom init.rc

Instead of using init.recovery.qcom.rc, replaces init.rc directly so that it
handles USB mass storage gadget in a better way, also doesn't break adb when
toggling mass storage mount.