Fix some documentation.

Fix some errors in the documentation of {string_writer,io}.{print,write}.

Clean up the formatting of the same documentation.

library/stream.string_writer.m:
	Fix a cut-and-paste errors: there is no string_writer.print/3
	predicate.

	s/pragma foreign_code/pragma foreign_type/ in a spot where
	the latter was meant.

	Refer to the destination stream as a string writer stream, rather
	than an output stream.

library/io.m:
	s/pragma foreign_code/pragma foreign_type/ in a spot where
	the latter was meant.
Fix a problem installing mfilterjavac on Windows.

mfilterjavac/Mmakefile:
	Don't accidentally drop the .exe extension in the install target.
Fix a compilation problem with MSVC.

scripts/mgnuc.in:
	C_COMPILER_TYPE still uses the cl_* style names, so we still need
	to match against that rather than msvc_*.
Fix errors in the operator table in the reference manual.

doc/reference_manual.texi:
    Remove character escapes from the operator table.
Fix github issue #14.

Compilation of the Boehm GC was failing on 64-bit openSUSE 13.1 because that
system defines site specific settings for configure scripts and one of those
site specific settings is that when using a 64-bit C compiler, the value of
--libdir should default to ${exec_prefix}/lib64.  For the Boehm GC, this means
that libatomic_ops was being installed libatomic_ops-install/lib64 rather than
libatomic_ops-install/lib.  The top-level Boehm GC Makefile expects to find it
in the latter.

boehm_gc/build_atomic_ops.sh:
	Explicitly set --libdir for libatomic_ops so that we override any
	site specific settings for configure and libatomic_ops is "installed"
 	in the correct directory.
Add .gitignore files to the extras/ directory

extras/.gitignore:
    Mercury ignores the --use-{grade}-subdir dir
    Mercury/** for git 1.8+ this recursively ignores all build files
    ignoring *.mh and *.init files
    *.err output files
    lib*.{dll|so|a|dylib} ignores target compiler library output
    *.jar ignores the Java grade output
    *.exe for Windows executables

extras/dynamic_linking/.gitignore:
    ignoring the copy of dl.m, name_mangle.m
    ignoring hello lib and dl_test* executables

extras/moose/samples/.gitignore:
    ignoring cgram.m small.m alpha.m expr.m which are
    generated from the .moo grammar files

extras/graphics/mercury_cairo/samples/.gitignore:
    ignoring *.png output and all executables

extras/**/.gitignore:
    In each sample/test/example folder the linux executable/test
    output is ignored
fix extras/graphics/ examples

Replace all occurances of index0_det with det_index0 to make these examples
compatible with recent versions of Mercury.

extras/graphics/easyx/samples/bounce.m:
extras/graphics/mercury_allegro/examples/exspline.m:
extras/graphics/mercury_allegro/samples/demo/aster.m:
extras/graphics/mercury_allegro/samples/speed/view.m:
    As above.