Deleting things often left measurements behind. Fixed these bugs, enhanced %del

to also delete frames and items in other frames than the current one, and added
the corresponding regression tests.

- fpd.y, README: %del can now also delete frames
- test/del_frame: regression test for frame deletion
- fpd.y: moved all debug items into debug_item, so that they can be invoked
  after defining measurements
- README: clarified that object labels aren't entirely hidden in the GUI
- delete.c (delete_references): also delete measurements referencing the frame
  (test/del_frame)
- fpd.y (dbg_link_frame): described why we need base_frame in addition to 
  base_vec
- fpd.y, README: %del can now also reach into frames other than the current one
- delete.c (do_delete_vec): also delete references in the root frame, i.e.,
  measurements (tests/del_vec)



git-svn-id: http://svn.openmoko.org/trunk/eda/fped@5947 99fdad57-331a-0410-800a-d7fa5415bdb3

README

@@ -588,7 +588,7 @@ Experimental: debugging directives
 For debugging and regression tests, fped supports the following commands,
 most of which mimick the effect of GUI operations:
 
-%del <identifier>
+%del <qualified-identifier>
 %move <identifier> [<number>] <identifier>
 %frame <identifier> <qualified-base>
 %print <expression>
@@ -596,14 +596,17 @@ most of which mimick the effect of GUI operations:
 %exit
 %tsort { -<id> | +<id> | <id-before> <id-after> [<number>] ... }
 
-%del and %move take as their first argument the name of the vector or
-object to manipulate. For this purpose, also objects can be labeled.
+%del removes the specified item. This can be a vector, an object, or
+a frame. If the vector or object is in a different frame than the
+current, its name is qualified with the frame name, e.g., "foo.obj".
 
-Object labels behave like vector labels and share the same name space.
-They are not shown anywhere in the GUI.
+For this purpose, also objects can be labeled. Object labels behave like
+vector labels and share the same name space.  They are not normally
+accessible in the GUI. (You can see them in the code view.)
 
-%move sets an anchor point to the vector named as its last argument.
-The anchor point is identified by index as follows:
+%move take as its first argument the name of the vector or object to
+manipulate. %move sets an anchor point to the vector named as its last
+argument. The anchor point is identified by index as follows:
 
 anchor index	vec/frame	line/rect/pad	arc		measurement
 --------------	---------	-------------	------------	-----------