delay test request randomly
decrease source files

move *.h -> defines.h
Merge branch 'issues/too_many_test_requests'
fix bug(somtimes infinite-loop occurs)
v0.7.2 released
fix problem(error handling leak)
v0.7.3 released
use pkg-config for searching libev and json-c path

The library and include paths for libev and json-c are fixed.
So building neoagent fails depending on theirs