[Settings]: recents panel clear all button tweaks

- Show or hide recents button
- Place the button in top right or left

@cristianomatos

Conflicts:
	res/values/cr_arrays.xml
	res/values/cr_strings.xml
	res/xml/crdroid_custom_settings.xml
	src/com/android/settings/crdroid/CustomSettings.java

Conflicts:
	res/values/strings.xml