new commit
Lots of improvements.  Fixed INCLUDE bug also.
Move specific timing model classes to separate files.
timing models: Change method for building full models from components.
timing_model: rearrange parfile parsing code a bit.
astrometry: add pm, px params; testing out some coordinate code.
timing_model: rearrange parsing code a bit more.
spindown: messing with python super()
Merge branch 'scott'
bug fix for add_alias
Separated commands from TOAs.  INFO, JUMPs, and PHASEs are now flags.
Was using wrong default value for EQUAD.  Should be 0.0
Merge branch 'jing'
Merge branch 'master' into toa_improvement
Added to_table() method
Use FORMAT command to help identify Tempo2 TOAs.  Add obss to table.
Fixed function name get_errors()
rearrange a little bit
Merge branch 'scott'

To get the newest version for other piece of code.
timing_model: call setup() after reading parfile.