GitLab

	1.support merge flash and userdata partition
	2.support configure otapackage filename and rkimage filename
	example: add ro.ota.packagename=rk_otapackage.zip to system/build.prop
	         add ro.rkimage.name=rk_image.img to system/build.prop
			(notice the filename extension must be 'img' or 'zip')
	3.fix download thread bug