Added relaxation of pad overlap checking. Not GUI-settable yet.

- README, fpd.l, fpd.y: added directives "allow touch" and "allow overlap" to
  make overlap checking more permissive
- dump.c (dump_allow, dump): generate "allow" directive
- obj.h, obj.c (allow_overlap): added global variable for strictness of overlap
  checking
- overlap.h, overlap.c (overlap, ...), layer.h, layer.c (refine_layers):
  strictness of overlap checking is passed as an argument
- hole.c (check_through_hole), layer.h, layer.c (refine_copper), obj.c
  (instantiate): updated callers of "overlap" to provide "allow" argument



git-svn-id: http://svn.openmoko.org/trunk/eda/fped@5974 99fdad57-331a-0410-800a-d7fa5415bdb3

README

@@ -106,7 +106,7 @@ The file has the following structure:
 frame definitions
 ...
 package name
-unit
+setup
 objects
 ...
 
@@ -124,6 +124,14 @@ from the previous vector to (2mm, 2mm), and then make a line connecting
 the two points.
 
 
+Setup
+- - -
+
+The setup section defines settings that affect the entire footprint.
+It is optional and can contain a "unit" directive and an "allow"
+directive.
+
+
 Units
 - - -
 
@@ -154,6 +162,24 @@ When saving a footprint definition, the default unit is set to the
 unit set in the GUI.
 
 
+Allow
+- - -
+
+fped normally disallows overlapping pads. This restriction can be
+relaxed with the "allow" directive. 
+
+allow touch
+
+Allows pads touching but not having more than their border in common.
+
+allow overlap
+
+Do not check for overlaps at all.
+
+If the "allow" directive is omitted, fped defaults to allowing
+neigher overlap nor touch.
+
+
 Vectors
 - - - -