Improve language colorizers (#54)

* fix detection of javascript partial comments in diff output
* colorize python annotations
* add simplistic yaml colorizer
* colorize .gitignore files
* improve shell buffer diff output colorization

lang/python.c

@@ -57,6 +57,7 @@ enum {
     PYTHON_STYLE_KEYWORD =  QE_STYLE_KEYWORD,
     PYTHON_STYLE_FUNCTION = QE_STYLE_FUNCTION,
     PYTHON_STYLE_REGEX    = QE_STYLE_STRING,
+    PYTHON_STYLE_ANNOTATION = QE_STYLE_PREPROCESS,
 };
 
 enum {  // Python flavors
@@ -103,6 +104,11 @@ static void python_colorize_line(QEColorizeContext *cp,
             style = PYTHON_STYLE_COMMENT;
             break;
 
+        case '@':
+            i += ustr_get_identifier(kbuf, countof(kbuf), c, str, i, n);
+            style = PYTHON_STYLE_ANNOTATION;
+            break;
+
         case '\'':
         case '\"':
             /* parse string constant */