showTimeToCompletion

 Prints the time to completion and expected finish of a looped simulation based on linear extrapolation.
 
 Syntax:    [ num_curr_char ] = showTimeToCompletion( percent_complete, num_prev_char )
   Note that before using this function in a loop the in-built MATLAB
   function tic should be called.
 
 Inputs: 
     percent_complete - A decimal number between 0 and 1 representing the
     percentage completion.
     num_prev_char - Number of previous characters printed to the screen
     (Usually ok to begin with 0 and then reuse num_curr_char)
 
 Outputs: 
     num_curr_char - Number of characters printed to the screen. Usually
     feed this number back into this function on the next iteration or
     increment appropriately if other characters have been printed between
     function calls.

 Example: 
       % Example 1
       fprintf('\t Completion: ');
       n=0; tic;
       len=1e2;
       for i = 1:len
           pause(1);
           n = showTimeToCompletion( i/len, n);
       end
       
       % Example 2
       fprintf('\t Completion: ');
       showTimeToCompletion; tic;
       len=1e2;
       for i = 1:len
           pause(1);
           showTimeToCompletion( i/len );
       end
       
       % Example 3
       fprintf('\t Completion: ');
       showTimeToCompletion; startTime=tic;
       len=1e2;
       p = parfor_progress( len );
       parfor i = 1:len
           pause(1);
           p = parfor_progress;
           showTimeToCompletion( p/100, [], [], startTime );
       end
 
 See also: tic, toc, parfor_progress