add Google AdMob Ads to login activity

the login activity may show up very fast, so be causion on this.

	modified:   .idea/compiler.xml
	modified:   .idea/workspace.xml
	modified:   AndroidManifest.xml
	modified:   assets/Version.txt
	modified:   res/layout/ad_layout.xml
	modified:   res/layout/main.xml
	modified:   src/com/quanta/pobu/apps/AutoGuest/AdPreference.java
	modified:   src/com/quanta/pobu/apps/AutoGuest/AutoGuestActivity.java
	modified:   src/com/quanta/pobu/apps/AutoGuest/AutoWiFiPreference.java