Eliminating doxygen warnings by fixing the documentation

* Fix "end of file while inside a group" doxygen warnings.

* Fix "unknown command" doxygen warnings caused by incorrect
  argument references. Instead of `@foo`, `@a foo` is the proper
  format.

* Fix "unknown command" doxygen warnings caused by incorrect
  parameter direction specifications. Instead of `@in`, `@out`,
  and `@in-out`, `[in]`, `[out]`, and `[in,out]` are the proper
  formats.

* Wrapping special characters in quotes to avoid doxygen
  confusion. Raw pipe, semicolon, dot, backslash, etc. characters
  can drive doxygen into various misinterpretations and warnings.
  E.g.:
  ```
  End of list marker found without any preceding list items
  Found unknown command
  ```
  Putting quotes around such text snipets eliminates the errors.

* Fix the documentation of `ecma_builtin_global_object_print`. Raw
  <> and \ sequences confused doxygen in various ways (it tried to
  interpret them as XML tags and doxygen commands).

* Fix "ignoring title that does not match old title" doxygen
  warnings. At some places, the group titles were out of sync, at
  others, the group names were incorrect.

* Fix "parameters are not documented" doxygen warnings. Fixing
  various typos in the inline parameter documentations (`/*`,
  `/**`, `/** <`, and `/**>` are all considered incorrect, the
  right format is `/**<`).

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu

jerry-core/ecma/operations/ecma-conversion.h

@@ -22,7 +22,7 @@
 /** \addtogroup ecma ECMA
  * @{
  *
- * \addtogroup ecmaconversion ECMA conversion
+ * \addtogroup ecmaconversion ECMA conversion routines
  * @{
  */
 

jerry-core/ecma/operations/ecma-objects.c

@@ -501,8 +501,8 @@ ecma_op_object_has_instance (ecma_object_t *obj_p, /**< the object */
  *         false if the target object is not prototype of the base object
  */
 bool
-ecma_op_object_is_prototype_of (ecma_object_t *base_p, /** < base object */
-                                ecma_object_t *target_p) /** < target object */
+ecma_op_object_is_prototype_of (ecma_object_t *base_p, /**< base object */
+                                ecma_object_t *target_p) /**< target object */
 {
   do
   {

jerry-core/ecma/operations/ecma-regexp-object.c

@@ -1176,7 +1176,7 @@ void
 re_set_result_array_properties (ecma_object_t *array_obj_p, /**< result array */
                                 ecma_string_t *input_str_p, /**< input string */
                                 uint32_t num_of_elements, /**< Number of array elements */
-                                int32_t index) /** index of matching */
+                                int32_t index) /**< index of matching */
 {
   /* Set index property of the result array */
   ecma_string_t *result_prop_str_p = ecma_get_magic_string (LIT_MAGIC_STRING_INDEX);