Added --print-target-path option.

If cc65 is installed and used as designed there's no need whatsoever for CC65_HOME (both on *IX and Windows) from the perspective of the cc65 binaries. If the user however has to access files from the 'target' directory thenhe ends up with some assumption on the cc65 installation path nevertheless :-(

In order to avoid this I added the --print-target-path option. It "exports" the logic used by the cc65 binaries to locate their files to the user thus allowing him to leverage the same logic to locate the target files in his build scripts / Makefiles.

doc/cl65.sgml

@@ -103,6 +103,7 @@ Long options:
   --o65-model model             Override the o65 model
   --obj file                    Link this object file
   --obj-path path               Specify an object file search path
+  --print-target-path           Print the target file path
   --register-space b            Set space available for register variables
   --register-vars               Enable register variables
   --rodata-name seg             Set the name of the RODATA segment
@@ -154,6 +155,14 @@ There are a few remaining options that control the behaviour of cl65:
   shouldn't use -o when more than one output file is created.
 
 
+  <tag><tt>--print-target-path</tt></tag>
+
+  This option prints the absolute path of the target file directory and exits
+  then. It is supposed to be used with shell backquotes or the GNU make shell
+  function This way you can write build scripts or Makefiles accessing target
+  files without any assumption about the cc65 installation path.
+
+
   <tag><tt>-t sys, --target sys</tt></tag>
 
   The default for this option is different from the compiler and linker in the
@@ -162,6 +171,7 @@ There are a few remaining options that control the behaviour of cl65:
   the C64 as a target system by default. This was chosen since most people
   seem to use cc65 to develop for the C64.
 
+
   <tag><tt>-Wa options, --asm-args options</tt></tag>
 
   Pass options directly to the assembler. This may be used to pass options
@@ -172,6 +182,7 @@ There are a few remaining options that control the behaviour of cl65:
   if cl65 supports an option by itself, do not pass this option to the
   assembler by means of the <tt/-Wa/ switch.
 
+
   <tag><tt>-Wc options, --cc-args options</tt></tag>
 
   Pass options directly to the compiler. This may be used to pass options
@@ -182,6 +193,7 @@ There are a few remaining options that control the behaviour of cl65:
   if cl65 supports an option by itself, do not pass this option to the
   compiler by means of the <tt/-Wc/ switch.
 
+
   <tag><tt>-Wl options, --ld-args options</tt></tag>
 
   Pass options directly to the linker. This may be used to pass options that
@@ -192,7 +204,7 @@ There are a few remaining options that control the behaviour of cl65:
   supports an option by itself, do not pass this option to the linker by means
   of the <tt/-Wl/ switch.
 
-</descrip>                        
+</descrip>
 
 
 
@@ -304,4 +316,3 @@ freely, subject to the following restrictions:
 
 
 </article>
-