Add mingw64.

- Rework patch.
- Rename mingw32-pdcurses-3.4-build.patch into mingw-pdcurses-3.4-build.patch.

mingw32-pdcurses-3.4-build.patch

@@ -1,63 +0,0 @@
-diff -Naur PDCurses-3.4.orig/win32/mingwin32.mak PDCurses-3.4/win32/mingwin32.mak
---- PDCurses-3.4.orig/win32/mingwin32.mak	2008-07-21 14:31:36.000000000 +0200
-+++ PDCurses-3.4/win32/mingwin32.mak	2012-04-20 15:28:55.071506378 +0200
-@@ -19,6 +19,7 @@
- PDCURSES_WIN_H	= $(osdir)/pdcwin.h
- 
- CC		= gcc
-+STRIP		= strip
- 
- ifeq ($(DEBUG),Y)
- 	CFLAGS  = -g -Wall -DPDCDEBUG
-@@ -30,8 +31,8 @@
- 
- CFLAGS += -I$(PDCURSES_SRCDIR)
- 
--BASEDEF		= $(PDCURSES_SRCDIR)\exp-base.def
--WIDEDEF		= $(PDCURSES_SRCDIR)\exp-wide.def
-+BASEDEF		= $(PDCURSES_SRCDIR)/exp-base.def
-+WIDEDEF		= $(PDCURSES_SRCDIR)/exp-wide.def
- 
- DEFDEPS		= $(BASEDEF)
- 
-@@ -50,7 +51,7 @@
- 
- ifeq ($(DLL),Y)
- 	CFLAGS += -DPDC_DLL_BUILD
--	LIBEXE = gcc $(DEFFILE)
-+	LIBEXE = $(CC) $(DEFFILE)
- 	LIBFLAGS = -Wl,--out-implib,pdcurses.a -shared -o
- 	LIBCURSES = pdcurses.dll
- 	LIBDEPS = $(LIBOBJS) $(PDCOBJS) $(DEFFILE)
-@@ -70,24 +71,24 @@
- libs:	$(LIBCURSES)
- 
- clean:
--	-del *.o
--	-del *.exe
--	-del $(CLEAN)
-+	-rm *.o
-+	-rm *.exe
-+	-rm $(CLEAN)
- 
- demos:	$(DEMOS)
--	strip *.exe
-+	$(STRIP) *.exe
- 
- $(DEFFILE): $(DEFDEPS)
- 	echo LIBRARY pdcurses > $@
- 	echo EXPORTS >> $@
--	type $(BASEDEF) >> $@
-+	cat $(BASEDEF) >> $@
- ifeq ($(WIDE),Y)
--	type $(WIDEDEF) >> $@
-+	cat $(WIDEDEF) >> $@
- endif
- 
- $(LIBCURSES) : $(LIBDEPS)
- 	$(LIBEXE) $(LIBFLAGS) $@ $?
--	-copy pdcurses.a panel.a
-+	-cp pdcurses.a panel.a
- 
- $(LIBOBJS) $(PDCOBJS) : $(PDCURSES_HEADERS)
- $(PDCOBJS) : $(PDCURSES_WIN_H)