Maven: Fixes at map-android and Samples pom files
merge master into dev (version on dev is dev-SNAPSHOT).
TileStoreLayer added: offline raster tiles in TMS storage format. Example use in TileStoreLayerViewer in Samples. Data sample in Samples/data/tilestore.
Scale bar: add Nautical miles as units system.
Improve API for setting scale bar mode and primary/secondary distance
adapter.
NauticalUnitAdapter: improvement at scale values
LabelsLayer: large changeset to separate label/icon display from the TileCacheLayer. This fixes problems of label layout, label clipping, label overwriting and goes a long way towards rotation. See mapsforge-map/docs/LabelLayer.md for more info.
Documentation: added Getting Started for Developers (from Google Code Wiki)
Awt: make BufferedImages from AwtBitmap accessible via AwtGraphicFactory
Cache: read/write locking on smaller regions to speed up cache performance
SwingMapViewer: make it compatible with LabelLayer mechanism
Cache: made the tile caches WorkingSetCaches that do not eject tiles that are currently visible.
Added getImmediately() to cache functions that will only return if the result is available in the fastest
cache level for a multi-level cache.
Merge branch 'master' into dev

Conflicts:
	Applications/Android/Samples/AndroidManifest.xml
	Applications/Android/Samples/pom.xml
	SwingMapViewer/pom.xml
	SwingMapViewer/src/main/java/org/mapsforge/map/swing/MapViewer.java
	build.gradle
	mapsforge-core/pom.xml
	mapsforge-map-android/pom.xml
	mapsforge-map-awt/pom.xml
	mapsforge-map-reader/pom.xml
	mapsforge-map-writer/pom.xml
	mapsforge-map/pom.xml
	mapsforge-map/src/main/java/org/mapsforge/map/layer/renderer/DatabaseRenderer.java
	pom.xml
	svg-android/pom.xml
Labels: mostly backed out of separate LabelLayer for performance reasons, labels are now written back on tiles with rewritten code for managing labels that overlap tile boundaries. Using an untiled LabelLayer remains an option, but is alpha at the moment (example in LabelLayerMapViewer in Samples). Reverted back to previous rendertheme-v4 for comparison purposes. Fix for coast line rendering.
CodeQuality: removed some unused lines of code, no functionality change.
MercatorProjection: reinstated getPixel(LatLong, byte, int). (Fixes double-tap zoom problem as code now linked against getPixel(LatLong, float, int))
Internal Rendertheme: adjusted dy values so that labels are again written above symbols (stations, etc).
LatLong: added distance operation used for determining closed polygons (rounding problems with doubles)
Fix for line-dotting on Android 2.3
MapDatabase: drop ways with invalid coordinates
AwtPointTextContainer: adjustments for label placement