Use .gitignore instead of .hgignore

Now that we've switched to git, let's use Git's ignore file instead of
Mercurial's.

.gitignore

+aclocal.m4
+autom4te.cache
+configure
+libtool
+Makefile
+Makefile.in
+stamp-h1
+config
+config.h
+config.h.in
+config.log
+config.status
+example-deconstructor
+example-deconstructor-alt
+example-reformatter
+example-reformatter-alt
+run-dumper
+run-emitter
+run-loader
+run-parser
+run-scanner
+.deps
+.libs
+*.o
+*.lo
+*.la
+*.pc

.hgignore

-syntax: glob
-aclocal.m4
-autom4te.cache
-configure
-libtool
-Makefile
-Makefile.in
-stamp-h1
-config
-config.h
-config.h.in
-config.log
-config.status
-example-deconstructor
-example-deconstructor-alt
-example-reformatter
-example-reformatter-alt
-run-dumper
-run-emitter
-run-loader
-run-parser
-run-scanner
-.deps
-.libs
-*.o
-*.lo
-*.la
-*.pc