test: added test 580 - verifies symbols-in-versions

The new perl script mk580.pl generates a C table in a fresh source file
named lib580.c and if that compiles fine we know that the file
docs/libcurl/symbols-in-versions at least doesn't include any symbols
that are misspelled.

An additional feature would be to somehow scan curl/curl.h and compare
with symbols-in-versions to see if there are symbols missing.