kconfig depends on gperf, flex, and bison. Mention these in README
Fix undefined reference to `led_toggle'
Use designated initializers for default resource declaration
More trailing whitespace
Fix NULL return check

Array indexing precedence is higher than dereferencing, so argv was
being indexed into, and then dereferenced, which meant that some unknown
address in memory was being checked for NULL.
Expand error messages and clarify malloc size

We are mallocing for an array of strings, so get space for the pointers
Add history command to shell
Add atoi() string conversion function
getchar: shell func to read character values