Add spell checking support (issue #137).

This includes:
- Red underline of misspelled words in html text areas.
- Right-click context menu options to correct the misspelled word.
- New CefBrowser::ReplaceMisspelling method for accepting a word replacement.
- Methods added to CefContextMenuParams for retrieving spelling-related information.
- Uses the unified text checker when auto-correct is not enabled to match Google Chrome behavior.
- On Windows and Linux a hunspell dictionary file will be downloaded to the "<cache_path>/Dictionaries" directory as needed, or used from the <cache_path> directory if the file already exists there. The dictionary file will be downloaded from http://cache.pack.google.com/edgedl/chrome/dict/<LANG>-3-0.bdic where <LANG> is the language abbreviation.
- On OS X the spell checking implementation will use the system NSSpellChecker implementation.

The following command-line flags have been added:
--disable-spell-checking => Disable spell-checking support (no red underline, no dictionary file download, etc).
--enable-spelling-auto-correct => Automatically correct common misspellings while typing (like 'omre' to 'more' on Windows/Linux or 'ehlo' to 'helo' on OS X).
--enable-spelling-service => Enable use of the remote Google spelling service (this requires Google API keys).
--override-spell-check-lang=<LANG> => Use the specified dictionary language <LANG> instead of the language specified in the locales.pak file. To see the default/supported dictionary languages: https://code.google.com/p/chromium/codesearch#search/&q=IDS_SPELLCHECK_DICTIONARY%20xtb&sq=package:chromium


git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@1859 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

include/cef_context_menu_handler.h

@@ -193,12 +193,40 @@ class CefContextMenuParams : public virtual CefBase {
   /*--cef()--*/
   virtual CefString GetSelectionText() =0;
 
+  ///
+  // Returns the text of the misspelled word, if any, that the context menu was
+  // invoked on.
+  ///
+  /*--cef()--*/
+  virtual CefString GetMisspelledWord() =0;
+
+  ///
+  // Returns the hash of the misspelled word, if any, that the context menu was
+  // invoked on.
+  ///
+  /*--cef()--*/
+  virtual int GetMisspellingHash() =0;
+
+  ///
+  // Returns true if suggestions exist, false otherwise. Fills in |suggestions|
+  // from the spell check service for the misspelled word if there is one.
+  ///
+  /*--cef()--*/
+  virtual bool GetDictionarySuggestions(std::vector<CefString>& suggestions) =0;
+
   ///
   // Returns true if the context menu was invoked on an editable node.
   ///
   /*--cef()--*/
   virtual bool IsEditable() =0;
 
+  ///
+  // Returns true if the context menu was invoked on an editable node where
+  // spell-check is enabled.
+  ///
+  /*--cef()--*/
+  virtual bool IsSpellCheckEnabled() =0;
+
   ///
   // Returns flags representing the actions supported by the editable node, if
   // any, that the context menu was invoked on.