better handling of option "Compatibility Function" on first activation

admin/qtx_activation_hook.php

@@ -469,6 +469,7 @@ function qtranxf_activation_hook()
 
 	}
 
+	// @since 3.3.7
 	if($check_qtranslate_forks){ // possibly first install after a fork
 		if( get_option('qtranslate_qtrans_compatibility') === false ){
 			//to prevent most of fatal errors on upgrade

readme.txt

@@ -104,9 +104,10 @@ Developers: please drop new topics here, the text will be moved to [qTranslate-X
 
 ### 3.3.7 ###
 * Feature: finalizing [Integration Framework](https://qtranslatexteam.wordpress.com/integration/).
+* Feature: swirly-bracket(brace) language encoding added to be used in places where square-bracket and comment encoding do not work. '[:]' sometimes conflict with shortcodes. '<!--:-->' does not survive tag clean up. '{:}'(swirly-bracket) seems to survive all.
 * Enhancement: 'plugins' vs 'mu-plugins', links of sub-folders, etc. [Issue #168](https://github.com/qTranslate-Team/qtranslate-x/pull/168).
 * Enhancement: gettext filters in raw and single language modes.
-* Feature: swirly-bracket(brace) language encoding added to be used in places where square-bracket and comment encoding do not work. '[:]' sometimes conflict with shortcodes. '<!--:-->' does not survive tag clean up. '{:}'(swirly-bracket) seems to survive all.
+* Enhancement: turn on 'Compatibility Functions' on first activation, if a file of one of the former forks is detected.
 * Fix: handling non-standard language code: [Issue #171](https://github.com/qTranslate-Team/qtranslate-x/issues/171).
 * Fix: 'Head inline CSS' update on language list changes.
 * Fix: pagination of posts under Query Mode of URL Modification (filter 'qtranxf_convertBlogInfoURL'): [Issue #155](https://github.com/qTranslate-Team/qtranslate-x/issues/155). Filters 'home_url' and 'bloginfo_url' are disabled in Query mode.