Fixes for cloned mode
Makefiles switch to LF only
Bilinear overview resampling pays attention to the NoData
Restored the GDAL provided overview building.
Use resampling mode "avg" to use the MRF internal one
Also pick overview scale from the first level scale, if not set up already
This makes powers of 3 level work
Undo the last change, which was a mistaken reversion
Support relative file names for data and index

The DataFile and Index file are considered relative to the metadata file
path if they contain no slashes or if they start with dots followed by
slashes.
Fix for absolute paths in DataFile and IndexFile
Merge pull request #8 from lucianpls/master

Merge fixes for #2