Test for large Zip archives, following code for large Tar test.

Test for large Zip archives, following code for large Tar test.
Fix several bugs:
 * comparison function for ordering entries in reader was wrong
 * writer wasn't including 64-bit sizes for entries of exactly 0xffffffff bytes
Also, add options to suppress CRC calculations and checks
(otherwise, this test spends a *lot* of time in CRC routines).