Added Postscript outout for measurements, plus assorted changes.

- postscript.c: added patterns backhatchpath and crosspath (for pad overlaid 
  with solder paste)
- postscript.c: added measurements
- postscript.c: prefixed style parameters with PS_ to avoid future conflicts
  with gui_style.h
- when changing the default unit, we now cancel the selection, and refresh 
  canvas and current position
- on-screen measurements now suppress the unit if set to anything but "auto"
- use  __attribute__((format(printf, ...))) for printf-like functions
- the unit selector now has a white background to make it clearer that it can 
  be clicked



git-svn-id: http://svn.openmoko.org/trunk/eda/fped@5461 99fdad57-331a-0410-800a-d7fa5415bdb3

Makefile

@@ -28,7 +28,7 @@ CFLAGS_GTK = `pkg-config --cflags gtk+-2.0`
 LIBS_GTK = `pkg-config --libs gtk+-2.0`
 
 CFLAGS_WARN=-Wall -Wshadow -Wmissing-prototypes \
-            -Wmissing-declarations
+            -Wmissing-declarations -Wno-format-zero-length
 CFLAGS=-g -std=gnu99 $(CFLAGS_GTK) -DCPP='"cpp"' $(CFLAGS_WARN)
 SLOPPY=-Wno-unused -Wno-implicit-function-declaration -Wno-missing-prototypes \
        -Wno-missing-declarations