format popup menu
make it beautiful!
Merge branch 'master' of https://github.com/tupini07/Android-Menus-Examples

Conflicts:
	app/src/main/res/values/strings.xml
Navigation issues
Merge branch 'master' of https://github.com/tupini07/Android-Menus-Examples

Conflicts:
	app/src/main/res/values/strings.xml
navigation buttons
Merge branch 'master' of https://github.com/tupini07/Android-Menus-Examples

Conflicts:
	app/src/main/java/com/pi314/android_menu_example/main_activity.java
	app/src/main/res/layout/activity_main.xml
	app/src/main/res/values/strings.xml