Change config.h.in to avoid clobbering command line defines, if given.

In gcc, a preprocessor definition in source code always takes precedence over one given on the command line. Putting conditionals in config.h.in (and therefore in the config.h that autotools creates) prevents clobbering command line definitions.
Revert "Change config.h.in to avoid clobbering command line defines, if given."

This reverts commit 4cde6569b4b82f4af6c5d32576b1b40bef914d60.
Delete the entire prototype directory, since it's been disused for years.

This removes several troublesome third-party software licenses from the Mapready repo.
Merge branch 'devel' of https://github.com/asfadmin/ASF_MapReady into devel
Install top-level Scons build files.
Remove hard-coded pathname, and allow install dir on command line.
Merge pull request #148 from ninneman/devel

Remove the disused prototype directory.