(add) pdf viewer
Merge branch 'master' of github.com:imhatep/physical_training

Conflicts:
	app/src/main/AndroidManifest.xml
	app/src/main/java/com/mil/physicaltraining/ActionsActivity.java
	app/src/main/res/values/strings.xml
(fix) errors when excel table import
(add) html viewer. exercises descriptions