Issue #152 (bdwgc).
* CMakeLists.txt (enable_munmap): New OPTION (on by default).
* CMakeLists.txt [enable_munmap] (USE_MMAP, USE_MUNMAP): Define macro.
* CMakeLists.txt [enable_checksums && enable_munmap): Issue MESSAGE
that CHECKSUMS is not compatible with USE_MUNMAP.
* configure.ac (AC_ARG_ENABLE(munmap)): Update the help message.
* configure.ac [$enable_munmap=""]: Treat as enable_munmap="yes".
* configure.ac [$MUNMAP_THRESHOLD=""]: Treat as MUNMAP_THRESHOLD="yes".
* doc/README.win32 (GNU Tools): Note about "--disable-munmap" option.
* doc/debugging.md (Unexpectedly Large Heap): Remove advice about
"--enable-munmap" option.
The "doc" files converted: debugging.html, finalization.html,
leak.html, porting.html, scale.html, simple_example.html.
* README.md: Replace leak.html with leak.md; replace debugging.html with
debugging.md.
* doc/debugging.html: Change file suffix to .md; convert text format
from HTML to Markdown.
* doc/finalization.html: Likewise.
* doc/leak.html: Likewise.
* doc/porting.html: Likewise.
* doc/scale.html: Likewise.
* doc/simple_example.html: Likewise.
* doc/gcdescr.html: Replace scale.html with scale.md; replace
finalization.html with finalization.md.
* doc/gcinterface.html: Likewise.
* doc/doc.am (dist_doc_DATA): Rename doc/debugging.html to
doc/debugging.md, finalization.html to finalization.md, leak.html to
leak.md, porting.html to porting.md, scale.html to scale.md,
simple_example.html to simple_example.md.
* doc/overview.html: Replace simple_example.html with
simple_example.md; replace leak.html with leak.md; replace scale.html
with scale.md; replace finalization.html with finalization.md; replace
debugging.html with debugging.md.
Ivan Maidanski