Small documentation fix
Fix spelling mistake
Release v0.4.1
Remove some vpcmp functions

These functions not only had incorrect prototypes, but were also
basically useless if pass to a map, since the void ptr was pointing to
an object with a private definition.

If the user needs to use these with a map then they should probably just
define their own comparison functions for struct autil_TYPE* instead.
Add autil_string_cmp and autil_string_vpcmp
Fix spelling mistake
Add helper functions for vec of string
Update internal documentation
Run clang-format
Add additional bigint test cases
Update internal documentation
Add perf/bigint-divrem-4096x64-bits.c
Add perf for bigint divrem
Make perf target automatically run all perf tests

If this target ends up taking a long time to run on one machine then the
behavior of the target may eventually get changed.
Remove duplicate logic
Add rudimentary performance testing

This commit adds a new directory, perf/, as well as a new make target,
perf, which builds a set of performance tests for the autil libraries.
Currently these tests are not very scientific, using only the standard
C99 clock() function over one iteration of the operation under test.

Future improvements should include use of either the Linux perf tool or
gprof as well as a better way to randomize performance test data.
Right now I really just wanted to get something simple that I could use
to roughly measure performance of the autil bigint functions.
Make aengn_sprite_del(NULL) a NOP
Add documentation for autil_string_split
Release v0.4.0
Revamp the bigint-calculator example

Turn the bigint-calculator.c example program into something closer to
what you would expect from a UNIX-like utility.
Instead of reading program arguments for the equation, the application
reads lines at a time from stdin until EOF is reached.
This new revamp also adds in better error messages and error checking.
Fix off-by-one error in autil_string_remove