varint - varint: Initial commit of an arbitrary precision unsigned

Log Message:
-----------
Initial commit of an arbitrary precision unsigned integer data type with
bitwise operators.

The following operators are implemented so far (not optimally, but I'm not
worried about that yet):
& (bitwise and)
| (bitwise or)
^ (bitwise xor)
<< (bitwise left shift)
>> (bitwise right shift)
+ (arithmetic add)
- (arithmetic subtract)
* (arithmetic multiply)

I plan to implement comparison operators and division next.

Added Files:
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varint:
Makefile (r1.1)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/varint/varint/Makefile?rev=1.1&content-type=text/x-cvsweb-markup)
varint.c (r1.1)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/varint/varint/varint.c?rev=1.1&content-type=text/x-cvsweb-markup)
varint.h (r1.1)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/varint/varint/varint.h?rev=1.1&content-type=text/x-cvsweb-markup)
varint.sql.in (r1.1)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/varint/varint/varint.sql.in?rev=1.1&content-type=text/x-cvsweb-markup)