fix eol-style

Bring in basic support for building the winnt MPM under mingw32, using the autoconf build system. Currently this will get you to the point of linking errors on gen_test_char. configure.in: Default to winnt MPM on mingw32 hosts. configure.in: Add AP_DECLARE_EXPORT for mingw32 hsots. os/config.m4: Use win32 dir under mingw32. os/win32/Makefile.in: Add in a new makefile to generate libos on win32. server/mpm/config.m4: Add winnt MPM to the help string. server/mpm/config.m4: winnt MPM is a threaded MPM. server/mpm/winnt/child.c: SO_UPDATE_ACCEPT_CONTEXT is defined under a different header in mingw32. server/mpm/winnt/{Makefile.in,config.m4}: Base build for winnt MPM. os/win32,server/mpm/winnt: Update svn:ignore for .deps/.libs