Fully implement overlapped I/O for Windows serial ports.
Allow creation and selection of truly empty chart groups.
Allow minimal builds from read-only source tree.
Improve raster texture cache file management.
Correct fault in options->ships->MMSI Properties "Edit" dialog
debug
Revert "debug"

This reverts commit a31305544e4d0ca66c9b92412c7abb88d01f5225.
Correct tide/current database location validation logic to allow arbitrary path.
Merge branch 'overlap'
Correct wording of MMSI Properties option "Handle this MMSI as SART/PLB MOB." (FS#1549)
Improve Options->Display->OpenGL Options default control enable settings.
Correct broken file selection in grib dialog
Apply global font to preferences dialog (forgetting)
Merge pull request #174 from Ptizef/master

Correct broken file selection in grib dialog
Implement chart zoom detail slider.
Correct compiler warning on Windows.
3.3.2301 (Alpha test)
Correct ENC display shortcut keys for A(nchor) and L(ights)  (FS#1368)
Merge branch 'master' of https://github.com/OpenCPN/OpenCPN
Improve JumpToPosition() logic for large scale changes.