Add icon link on link and open it on clic
open by clicking only if childless
Android 4.4 permission issue
Change icon if node is clicked : checked-->unchecked ;
unchecked-->checked
Test if link starts with http
last image name in richcontent as node name if no text
fix  "Add icon link on link and open it on clic" : search img not
recursively
convert richcontent node to simple text node
Migrated to Gradle and AndroidStudio
Merge branch 'master' of https://github.com/jertux/droidplane into merge-jertux

Changes:
- tapping a leaf node with a link opens link
- convert richtext nodes to string (using HTML lib)

Conflicts:
	AndroidManifest.xml
	project.properties
	src/ch/benediktkoeppel/code/droidplane/MindmapNode.java