Rename template - what is it?
-----------------------------

This a feature of renaming files according to a specified template. Syntax of the 
template is very simple: all chars of the template go into new name with the exception 
of a few placeholders:

$N	the whole file name (with extension)
$N(2,3)	3 chars of the file name starting at the position of 2
$N(5)	all chars of the file name starting at the position of 5
$n	file name without extension
$n(...)	the same like $N(...)
$e	file extension
$e(...)	the same like $N(...)
$p	parent dir name
$p(...)	the same like $N(...)
$g	grandparent dir name
$g(...)	the same like $N(...)
$c	counter
$c(3)	counter with specified digit number (precision)
$$	dollar sign

Additionally strftime() format controls are also accepted - except for %D, %n and %t for 
obvious reasons. If found, they are converted into single %.
 
For example - renaming the pictures:

template:  'Holidays - $p %Y.%m #$c.$e'

'~/pix/Barcelona/pic00135.jpg'  --> 'Holidays - Barcelona 2002.09 #01.jpg'
'~/pix/Barcelona/pic00145.jpeg' --> 'Holidays - Barcelona 2002.09 #02.jpeg'
'~/pix/Rome/pic00248.png'       --> 'Holidays - Rome 2002.10 #03.png' 

Broken placeholders - like $n(), $e(0,3) or $N(abc) - are copied verbatim without any 
substitution.
