fixes issue #29
org-mode session, lp:1119201

Thanks Alexander Boettcher
`py-hungry-delete-forward', `py-hungry-delete-backwards' in menu PyEdit
py-electric-backspace new feature

- new boolean `py-electric-kill-backward-p', default is nil.
  If behind a delimited form of braces, brackets or parentheses,
  py-electric-backspace will kill it's contents

  With when cursor after
  mystring[0:1]
  -------------^
  ==>
  mystring[]
  ---------^
  In result cursor is insided emptied delimited form."

- unused variable `py-backspace-function' removed

py-version in developing branch (trunk) now "6.1.2"

Unused variable `py-backspace-function' removed
py-electric-backspace new feature

- new boolean `py-electric-kill-backward-p', default is nil.
  If behind a delimited form of braces, brackets or parentheses,
  py-electric-backspace will kill it's contents

  With when cursor after
  mystring[0:1]
  -------------^
  ==>
  mystring[]
  ---------^
  In result cursor is insided emptied delimited form."

- unused variable `py-backspace-function' removed

py-version in developing branch (trunk) now "6.1.2"

Unused variable `py-backspace-function' removed