BF: replace 32 bit linux slave

I gave the old 32 bit machine to another lab.
RF: use slave_pass file for slave passwords

Further definition of slaves goes in the nibotmi file.  Thus adding a
slave is

1. Adding the name and password to the slave_pass.py dictionary
2. Defining properties of said slave in master.cfg file, such as aliases
   etc
DOC: notes about how buildbot works
NF: add windows bdist factory
NF: add first win7 builders

nibabel tests and bdist builders for win7
NF: add gitpoller scheduler for nibabel win7
NF: add doc build scheduler
Fix doc_factory to return factory
Fixup messed up brackets etc for doc builder
NF: add nibabel doc build, move doc output
NF: gitignore for all those stray files
Move to intel 10.6 naming for mikesilver slave
Fix deployment target for 10.6
RF: switch to 10.6 builder name from 10.4
RF: refactor doc and code builders

Put more definitions into the github containers and use these as defaults. Add
changesource to nightly schedulers - it seems they are needed to identify the
repository to the builder.
RF: use virtual frame buffer for dipy linux builds

The dipy builds on linux were calling traitsui or VTK and then crashing due to
the lack of an X display.  Work round this by using a virtual frame buffer.
NF: add startup script for jcirl machine
BF: correct vim syntax specifier
RF: remove python2.5 testing for dipy

Dipy now needs python 2.6
RF: add nipy binary builders for osx and windows