coyote: CGNUMBER_FORMATTER

Description
This is a utility routine format a number into a string. It is used primarily for 
formatting numbers that will appear in text widgets in widget programs.
Categories
Utilities
Returns
A string with the formatted number or numbers is returned.
Params
number: in, required
   The number to be turned into a string. May be any data type except complex, 
   double complex, pointer or object. May be an array of numbers.
Keywords
decimals: in, optional, type=integer, default=2
    Set this keyword to the number of decimal places to be included to the right of 
    the decimal point in floats and doubles. Set to 2 by default. In numbers with
    absolute values between 0 and 1, the number of decimals is equivalent to the
    number of significant digits. See the example below.
Examples
Here is how to use this program::
    IDL> array = [45.123456, -30.123456, !Values.F_Nan, !Values.F_Infinity, $
                  0.00123456, -0.00123456, 0.0123456, 0.123456, 1.234567]
    IDL> FOR j=0,N_Elements(array)-1 DO Print, Number_Formatter(array[j], Decimals=4)
    45.1235
    -30.1235
    NaN
    Inf
    0.001235
    -0.001235
    0.01235
    0.1235
    1.2346
Author
FANNING SOFTWARE CONSULTING::
   David W. Fanning 
   1645 Sheely Drive
   Fort Collins, CO 80526 USA
   Phone: 970-221-0438
   E-mail: david@idlcoyote.com
   Coyote's Guide to IDL Programming: http://www.idlcoyote.com
History
Change History::
   Written, 8 November 2012 by David W. Fanning from the retired Number_Formatter program.
   The algorithm I was using for numbers between 0 and 1 used a LT in the Where function to
       find an index. It appears this should have been a LE, instead. 11 Jan 2013. DWF.
Copyright
Copyright (c) 2012, Fanning Software Consulting, Inc.