Find bundled ICU in workdir and use debug .libs when needed

diff -up win32/Makefile.msvc.dt win32/Makefile.msvc
--- win32/Makefile.msvc.dt	2014-07-18 19:00:23.372103963 +0200
+++ win32/Makefile.msvc	2014-07-18 19:01:39.347982929 +0200
@@ -42,6 +42,7 @@
 CC = cl.exe
 CFLAGS = /nologo /D "_WINDOWS" /D "_MBCS" /D "NOLIBTOOL" /W3 /wd4244 /wd4267 $(CRUNTIME)
 CFLAGS = $(CFLAGS) /I$(XML_SRCDIR) /I$(XML_SRCDIR)\include /I$(INCPREFIX)
+CFLAGS = $(CFLAGS) /I$(WORKDIR)/UnpackedTarball/icu/source/i18n /I$(WORKDIR)/UnpackedTarball/icu/source/common
 !if "$(WITH_THREADS)" == "ctls"
 CFLAGS = $(CFLAGS) /D "XML_THREAD_LOCAL=__declspec(thread)"
 !else if "$(WITH_THREADS)" == "posix"
@@ -62,7 +63,9 @@
 # The linker and its options.
 LD = link.exe
 LDFLAGS = /nologo /VERSION:$(LIBXML_MAJOR_VERSION).$(LIBXML_MINOR_VERSION)
+LDFLAGS = $(LDFLAGS) /LIBPATH:$(WORKDIR)/UnpackedTarball/icu/source/lib
 LDFLAGS = $(LDFLAGS) /LIBPATH:$(BINDIR) /LIBPATH:$(LIBPREFIX)
+LDFLAGS = $(LDFLAGS) /DEBUG /OPT:REF
 LIBS =
 !if "$(WITH_FTP)" == "1" || "$(WITH_HTTP)" == "1"
 LIBS = $(LIBS) wsock32.lib ws2_32.lib
@@ -74,9 +77,13 @@
 !if "$(STATIC)" == "1"
 LIBS = $(LIBS) advapi32.lib sicuuc.lib sicuin.lib sicudt.lib
 !else
+!if "$(DEBUG)" == "1"
+LIBS = $(LIBS) icuind.lib icuucd.lib icudtd.lib
+!else
 LIBS = $(LIBS) icuuc.lib icuin.lib icudt.lib
 !endif
 !endif
+!endif
 !if "$(WITH_ZLIB)" == "1"
 # could be named differently zdll or zlib
 # LIBS = $(LIBS) zdll.lib