libcygwin.a.
* rmsym: Delete.
* newsym: Delete.
* Makefile.in (toolopts): New variable which holds options relating to
binutils/gcc tools.
(speclib): Use toolopts. Add symbols to avoid copying to special libraries.
(OBSOLETE_FUNCTIONS): Delete.
(NEW_FUNCTIONS): Change to represent an argument to new mkimport script.
(libcygwin.a): Use only new mkimport script to create libcygwin.a. Only rely
on ${LIBCOS}.
(*/lib*.a): Simplify speclib dependencies.
(speclib): Accept toolchain options. Convert every argument to absolute path.
Simplify parsing of nm output. Accommodate new exclude option.
