Added functions to remember a set of include search paths and to search

for includes in these directories. Extended the scanner to use the new
functions.
Added several command line switches, including -I (--include-dir) to use
the new include search feature.


git-svn-id: svn://svn.cc65.org/cc65/trunk@12 b7a2c559-68d2-44c3-8de9-860c34a00d81

src/ca65/make/gcc.mak

@@ -13,6 +13,7 @@ OBJS =  condasm.o	\
 	fname.o	      	\
 	fragment.o	\
         global.o       	\
+	incpath.o	\
         instr.o	      	\
 	listing.o	\
 	macpack.o     	\

src/ca65/make/watcom.mak

@@ -70,6 +70,7 @@ OBJS = 	condasm.obj	\
 	fname.obj	\
 	fragment.obj	\
 	global.obj	\
+	incpath.obj	\
        	instr.obj	\
 	listing.obj	\
 	macpack.obj	\
@@ -113,6 +114,7 @@ FILE expr.obj
 FILE fname.obj
 FILE fragment.obj
 FILE global.obj
+FILE incpath.obj
 FILE instr.obj
 FILE listing.obj
 FILE macpack.obj