1.how to perform automatically update:
	a)change the values of the keys "versionCode" and "versionName" both in "AndroidMainifest.xml" and "ver.php", and make sure the 2 pairs match to each other.and, we will judge the version by "versionCode".
	b)put the apk file on server of the url that the member mUrlUpdate of LetuseeActivity point to.
	c)renew (by usring git is prefered) ver.php on server of the url that the member mUrlSite of LetuseeActivity point to.
2.continued...