Update help files.

runtime/doc/eval.txt

@@ -1,4 +1,4 @@
-*eval.txt*	For Vim version 7.4.  Last change: 2015 Jun 19
+*eval.txt*	For Vim version 7.4.  Last change: 2015 Jun 26
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -1005,7 +1005,7 @@ function.  Example: >
 
 
 
-string						*string* *expr-string* *E114*
+string					*string* *String* *expr-string* *E114*
 ------
 "string"		string constant		*expr-quote*
 
@@ -5839,15 +5839,17 @@ str2nr( {expr} [, {base}])				*str2nr()*
 		Text after the number is silently ignored.
 
 
-strchars({expr})					*strchars()*
+strchars({expr} [, {skipcc}])					*strchars()*
 		The result is a Number, which is the number of characters
-		String {expr} occupies.  Composing characters are counted
-		separately.
+		in String {expr}.
+		When {skipcc} is omitted or zero, composing characters are
+		counted separately.
+		When {skipcc} set to 1, Composing characters are ignored.
 		Also see |strlen()|, |strdisplaywidth()| and |strwidth()|.
 
 strdisplaywidth({expr}[, {col}])			*strdisplaywidth()*
 		The result is a Number, which is the number of display cells
-		String {expr} occupies on the screen when it starts a {col}.
+		String {expr} occupies on the screen when it starts at {col}.
 		When {col} is omitted zero is used.  Otherwise it is the
 		screen column where to start.  This matters for Tab
 		characters.