chugin ck_info() support added to host

[gewang]

chugins can now implement a "info query function" to provide chugin-specific information to be accessible from host, including:
* chugin version (not to be confused with compatibility version)
* chugin author(s)
* chugin description
* (optional) chugin URL
* (optional) contact email

for example, in the chugin source:

// chugin info func
CK_DLL_INFO( MyChugin )
{
    // set info
    QUERY->setinfo( QUERY, CHUGIN_INFO_AUTHORS, "Ana B. Croft" );
    QUERY->setinfo( QUERY, CHUGIN_INFO_CHUGIN_VERSION, "v3.6.1" );
    QUERY->setinfo( QUERY, CHUGIN_INFO_DESCRIPTION, "what does it do?" );
    QUERY->setinfo( QUERY, CHUGIN_INFO_URL, "https://foo.com/FooBar" );
    QUERY->setinfo( QUERY, CHUGIN_INFO_EMAIL, "[email protected]" );
}

this information is read by the host (and will be read even if the API compatibility check fails, as long as the chugin implements the CK_DLL_INFO function)