* New string property subtype: PASSWORD

When this new subtypes is used, then string of property is hidden using
asterisks, e.g.: mysecretpassword -> ****************

This code was reviewed and modified by Brecht. Thanks very much:
- https://codereview.appspot.com/6713044/

This new subtype of string property is intended mostly for Add-on developers
writing Add-on which communicates with some server (http, sql, ftp, verse,
etc.). When this server requires user authentication and user has to type
username and password, then current API didn't allow to type 'hidden' password,
e.g. when you want to demonstrate this script, then everybody can see this
security password. Some examples of Add-on which could use this new subtype:
- On-line database of textures
- Integration of render farm
- Integration of Verse

Security Notes:
- You can copy paste hiddent string of property from text input using (Ctrl-C, Ctrl-V),
but you can do this in other GUI toolkits too (this behavior it is widely used).
- Text of string property is stored in plain text, but it is widely used in other
GUI toolkits (Qt, Gtk, etc.).

Simple examples:
- https://dl.dropbox.com/u/369894/draw_op_passwd.py
- https://dl.dropbox.com/u/369894/blender-password.png

* Fix small bug in Python operator example; improved example of modal operator

- Blender could be build with scons again.

Fixed compile error on Fedora 15, when FFMPEG was enabled.

2.5 MetaBalls and UI

* Added callback function for some metaball properties:
When some properties (wiresize, threshold, update flags) of metaball are changed, then these properties are copied to all metaballs in the group (all metaballs with same base name). This is important to "share" some properties between metaballs, because polygonisation of metaball is influenced only by properties of base metaball and base metaball can be changed.
* Improved drawing of selected Metaball objects

- Fix some things I missed in my last commit
- Change name of OBJECT_OT_object_add operator
- Use new OBJECT_OT_object_add operator in space_info.py

2.5 MetaBalls

- It is possible to work with MetaBalls in edit mode now
- Added basic UI to the button window (feel free to change it :-))
- Header menus should work
- Undo & redo should work
- Removed global variable editelems and lastelem (moved it to the MetaBall struct)
- All tools from old editmball.c was converted to the operators
- Added lastelem to the RNA
- Experimental: mb->editelems is only pointer at mb->elems or NULL (depends on Mode). ListBase of MetaElems is not duplicated in edit mode.

Tested with scons at Linux and mac OS X

TODO:
- Recalc data after Undo or Redo
- Solve issue with basic MetaBall and Python UI script (only base MetaBall object influence Wiresize and Threshold)
- Fix orientation of manipulator in "Normal mode"

Small fix to be able to compile Blender.

Last bug fix of #10999. This should finaly work (tested by jesterking).

Bug fix of #10999. mbproc->start was useless.