Merge pull request #26 from MatthewFluet/pre-201306-release

Initial work for 201306?? release.
Link against libmlton-gdb.a when compiling with '-debug true' or '-debug-runtime true'.
Update MLYacc library to pass both left and right position of token to error function.

Thanks to René Neumann for the bug report.
Merge pull request #27 from MatthewFluet/link-libmlton-gdb

Link against libmlton-gdb.a when compiling with '-debug true' or '-debug-runtime true'.
Merge pull request #28 from MatthewFluet/mlyacc-lib-error-fn

Update MLYacc library to pass both left and right position of token to error function.
Upgrade gdtoa.tgz.
Update 'real' and 'real-int' regression output.

Older versions of gdtoa.tgz sometimes produced too many digits for
float/Real32 to string conversions.
Rename "Real<N>.strto" helper function to "Real<N>.strtor".

Rename to match gdtoa.tgz function.
Merge pull request #30 from MatthewFluet/gdtoa-upgrade

Upgrade gdtoa.tgz.
Merge branch 'master' of https://github.com/MLton/mlton into pre-201306-release