tool_doswin: Improve sanitization processing

- Add unit test 1604 to test the sanitize_file_name function.

- Use -DCURL_STATICLIB when building libcurltool for unit testing.

- Better detection of reserved DOS device names.

- New flags to modify sanitize behavior:

SANITIZE_ALLOW_COLONS: Allow colons
SANITIZE_ALLOW_PATH: Allow path separators and colons
SANITIZE_ALLOW_RESERVED: Allow reserved device names
SANITIZE_ALLOW_TRUNCATE: Allow truncating a long filename

- Restore sanitization of banned characters from user-specified outfile.

Prior to this commit sanitization of a user-specified outfile was
temporarily disabled in 2b6dadc because there was no way to allow path
separators and colons through while replacing other banned characters.
Now in such a case we call the sanitize function with
SANITIZE_ALLOW_PATH which allows path separators and colons to pass
through.


Closes https://github.com/curl/curl/issues/624
Reported-by: Octavio Schroeder

src/Makefile.am

@@ -75,8 +75,9 @@ curl_DEPENDENCIES = $(top_builddir)/lib/libcurl.la
 # if unit tests are enabled, build a static library to link them with
 if BUILD_UNITTESTS
 noinst_LTLIBRARIES = libcurltool.la
-libcurltool_la_CPPFLAGS = $(LIBMETALINK_CPPFLAGS) $(AM_CPPFLAGS)
-libcurltool_la_CFLAGS = -DUNITTESTS
+libcurltool_la_CPPFLAGS = $(LIBMETALINK_CPPFLAGS) $(AM_CPPFLAGS) \
+                          -DCURL_STATICLIB -DUNITTESTS
+libcurltool_la_CFLAGS =
 libcurltool_la_LDFLAGS = -static $(LINKFLAGS)
 libcurltool_la_SOURCES = $(curl_SOURCES)
 endif