- keyboard functions for the canvas: - zoom out, + or = zoom in, . center,

* zoom and center to extents
- variables in tables weren't properly initialized, causing stray recursive
  evaluation errors
- replaced table->active index with table->active_row pointer
- added row selection
- for fun, added tab.fpd row selection example 



git-svn-id: http://svn.openmoko.org/trunk/eda/fped@5375 99fdad57-331a-0410-800a-d7fa5415bdb3

README

@@ -337,3 +337,15 @@ Expressions
 Expressions can contain numeric constants (in non-exponential notation),
 variable names, the arithmetic operations +, -, *, /, and unary -.
 Parentheses can be used to change precedence.
+
+
+GUI
+---
+
+Keys:
+
+space	reset user coordinates
++, =	zoom in (like mouse wheel forward)
+-	zoom out (like mouse wheel backward)
+.	cursor position to screen center (like middle click)
+*	zoom and center to extents