resolver+constants README.md

allow macro usage within README.md
automatically handle README.md with add_plugin
add possibility for #include ELEKTRA_README(myplugin)
document that stuff in tutorial
constants: correctly use keyAddName and not keyAddBaseName
modernize template

use add_plugin
add a plugin test
add README.md for #59
export contract
allow to pass check
add check
improve copy-template
add <kdbhelper.h> in kdbplugins.h to have elektra* methods
fix noresolver readme inclusion