Add Wi-Fi Access Points scanning option

Adding Wi-Fi Access Points scanning in setting for enhancement on #241
Allow any tile server to be specified at build time
Merge pull request #252 from thefinn93/customTileServer

Custom tile server
Revert "Add Wi-Fi Access Points scanning option"

This reverts commit 51a10b79a3a02cd309eeb3d6e5784453b99550cf.
Block DB on-train WiFi 

See http://www.bahn.com/i/view/mdb/bahnintern/services/mobilitaet_service/zug/wlan/mdb_114824_www_im_ice_hot_spot_04_2013.pdf
Don't scan when Wi-Fi turned off
Merge pull request #254 from evilpie/patch-1

Block DB on-train WiFi
Don't scan when Wi-Fi turned off
Merge branch 'master' of https://github.com/xsoh/MozStumbler
Merge pull request #248 from xsoh/master

Add Wi-Fi Access Points scanning option
Fix typo
Remove TileSourceFactory.FIETS_OVERLAY_NL layer

This improves loading speed significantly
Set aTileSizePixels to 256

This fixes many 'java.lang.IllegalArgumentException: Problem decoding into
existing bitmap'.
MapBox returns 256x256 PNG tiles regardless of this parameter.
Use http:// instead of https:// Mapbox URL's

This speeds up tiles loading and fixes exception of strict mode: 'Explicit termination method 'close' not called'.
Disable hardware acceleration for MapActibity
OSMDroid does not support hardware acceleration yet
Clear tile cache when the activity is stopped
Reduce zoom levels range
Remove unused code
Add AccuracyCircleOverlay to map only once when the activity is created
Merge pull request #255 from illarionov/mapFixes0

Map improvements