Moved checkpoints out of main, to prep for using them to help prevent DoS attacks

src/makefile.mingw

@@ -29,6 +29,7 @@ CFLAGS=-mthreads -O2 -w -Wno-invalid-offsetof -Wformat $(DEBUGFLAGS) $(DEFS) $(I
 HEADERS = \
     base58.h \
     bignum.h \
+    checkpoints.h \
     crypter.h \
     db.h \
     headers.h \
@@ -58,6 +59,7 @@ endif
 LIBS += -l kernel32 -l user32 -l gdi32 -l comdlg32 -l winspool -l winmm -l shell32 -l comctl32 -l ole32 -l oleaut32 -l uuid -l rpcrt4 -l advapi32 -l ws2_32 -l shlwapi
 
 OBJS= \
+    obj/checkpoints.o \
     obj/crypter.o \
     obj/db.o \
     obj/init.o \