[KARAF-2760]monitor etc/user.properties change with felix FileInstaller
(cherry picked from commit 2cf592365f7a6a100107fda7bf40b6e8f15e95d2)

Conflicts:
	jaas/modules/src/main/java/org/apache/karaf/jaas/modules/properties/PropertiesLoginModule.java
(cherry picked from commit a60cec5bdc0c7b2e8777a03937d3409f90db8ca9)