Added test to check download_file error type (issue pointed out by @kbarbary)
Fix attempt to access errno when the exception sometimes doesn't have it

Closes #808
Fix compatibility with Numpy 1.4.1
Change Table so assigning to non-existent col name creates new column with that value
Allow for multidimensional data when setting with t['new'] = newcol
Check that item is string when creating a new table column

Previous version broke setting rows with t[1] = (values) because
it tried to create a new column 1.  Instead make sure the item is
a string and is therefore referring to a column name.
Fix problem adding new column to an empty table
Add tests for creating a new column using item setter
Propagate Column metadata when creating column using item setter
Change table setitem so a masked column can be added
Update table docs to use setitem syntax for adding a column
Fix scripts/README.rst bug
time.sleep(-1) hangs indefinitely on Windows (apparently by design).  Since the purpose of passing this value in the test was to test the behavior of bad input to a function being timed, let's instead use something that is unambiguously bad input for time.sleep() on all platforms.
Change the default floating point output in VOTable from '%g' to '%s'.  This does a better job of showing "enough" precision to correctly roundtrip the values.
Merge pull request #854 from iguananaut/issue-854

test_timer hanging on Windows.
Change from np.array to asarray when setting from non-ndarray item
Merge pull request #852 from weaverba137/fix-setup

Fix scripts/README.rst bug
Add TimePlotDate format for input to matplotlib plot_date()
Add test of TimePlotDate
Add example of using plot_date format with plt.plot_date()