fixed minor typo in spelling
Added several numpy number types to _compatibleNumericType. The ndarray was not sufficient to cover those types. This patch is needed to enable units to be used with the values returned by many numpy functions.
Add gt, lt, ge, le comparison operators.
add floor function for units
add ceil function
add rint
add round and around
add trunc
add sqrt
add long integer as compatible numeric type
add __mod__ function
added full signature for ceil, rint and floor. Note, however, that it does not seem to work to assign the results to other arrays yet. I am not sure why yet.
add fix function. it does not work, and is not called when numpy.fix is called. The fix function still does not work, and gives this traceback:

Traceback (most recent call last):
  File "C:\Users\jkitchin\Dropbox\python\scimath\scimath\units\tests\test_fix.py", line 24, in <module>
    print np.fix(a)
  File "C:\Python27\lib\site-packages\numpy\lib\ufunclike.py", line 48, in fix
    y[...] = nx.where(x >= 0, y1, y2)
  File "c:\Users\jkitchin\Dropbox\python\scimath\scimath\units\unit.py", line 79, in __ge__
    if not self.derivation == other.derivation:
AttributeError: 'int' object has no attribute 'derivation'
added checks to comparison operators to raise a meaningful exception if units are compared to non-unit objects.
add a set of tests for scimath.units.unit functionality