Consider using the Projection to handle "safe" drawing

[osmdroid]

Consider using the Projection to handle "safe" drawing

[kurtzmarc]

See branch SafeCanvas_To_Projection_Changes

[MKergall]

Hi Marc,

I just got an issue using Android Region, related to this extremely large canvas: Region is using 32 bit values, which can be ok or too small, depending on the position on the map, even at usual zoom levels (see http://code.google.com/p/osmbonuspack/issues/detail?id=59#c3).

Using the Projection for all lat/long <-> Pixel conversions seems to me the right approach.

If you deeply revise the Projection formulas, could you also handle floating zoom levels?... This is the must-have on the top of the list, I think.

[kurtzmarc]

This is complete and working well. Merging will happen soon if there is no additional feedback.

[kurtzmarc]

Merged in to master