Installation instruction

Thanks, I will take a look. I didn't realize that python-tk was a dependency, but we can take care of this by adding the dependency to setup.py.

I'm fairly new to Python, so not knowing any better I did a pretty ugly experiment to determine where this dependency was coming from. I removed python-tk from my system, and ran the following:

>>> from pylab import date2num, num2date, drange
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/pymodules/python2.6/pylab.py", line 1, in <module>
    from matplotlib.pylab import *
  File "/usr/lib/pymodules/python2.6/matplotlib/pylab.py", line 247, in <module>
    from matplotlib.pyplot import *
  File "/usr/lib/pymodules/python2.6/matplotlib/pyplot.py", line 78, in <module>
    new_figure_manager, draw_if_interactive, show = pylab_setup()
  File "/usr/lib/pymodules/python2.6/matplotlib/backends/__init__.py", line 25, in pylab_setup
    globals(),locals(),[backend_name])
  File "/usr/lib/pymodules/python2.6/matplotlib/backends/backend_tkagg.py", line 7, in <module>
    import Tkinter as Tk, FileDialog
  File "/usr/lib/python2.6/lib-tk/Tkinter.py", line 42, in <module>
    raise ImportError, str(msg) + ', please install the python-tk package'
ImportError: No module named _tkinter, please install the python-tk package

Assuming pylab is the only package that depends on python-tk, we should be able to get rid of pylab as a dependency by using Trac's datetime utils. This will be one of the tasks in the major rework of this plugin.

The TracMetrixPlugin wiki page has been updated to list the dependency. The dependency will be added to setup.py on the next check-in.

(In [9432]) Added required packages to setup.py. Refs #7986.

I added the other required packages to setup.py, but haven't figured out how to add python-tk as a requirement. Any ideas?