** Split standards-compliance mode and maintainer mode compiler flags out of CFLAGS, so that compilation command lines that do not generate (too many) warnings or are not forced to comply with ISO C '90 can be constructed without having to resort to stripping individual flags out of CFLAGS.
** Allow optimization and debugging to coexist, including in maintainer mode, adding a new configure option --enable-optimize. Neither --enable-optimize nor --enable-debug will override any optimization or debugging flags set by the user in C(XX)FLAGS at configure time. If debugging and optimization are enabled at the same time, we will try to use -O1, then -O; if debuggin is not enabled, we will try -O2 first.
** Move the sqlite-amalgamation directory from the root of the source tree under subversion/include/private to make include paths safer from possible collision with sqlite include files from other install locations.