Checking in on a tag is evil, but the code for finding

Inno Setup was completely broken.

inst/WinBuilders/mk/common.mk

@@ -39,8 +39,8 @@ TOUCH=touch
 NMAKE=nmake
 CSCRIPT=cscript
 ECHO=echo
-ISS_DIR=$(PROGRAMFILES)\\Inno Setup 5
-ISS_COMPILER=$(ISS_DIR)\\Compil32.exe
+ISS_DIR=$(CYGROOT)/Progra~1/Inno Setup 5
+ISS_COMPILER=$(ISS_DIR)/Compil32.exe
 # We need a version that understands cygwin paths, so /bin/
 UNZIP=/bin/unzip