unicode: optional table for better handling of neutral bidi chars

Off:
function                                             old     new   delta
unicode_bidi_isrtl                                     -      55     +55
isrtl_str                                             51      65     +14
unicode_isrtl                                         55       -     -55
read_line_input                                     5003    4937     -66
------------------------------------------------------------------------------
(add/remove: 1/4 grow/shrink: 1/1 up/down: 69/-121)           Total: -52 bytes

On:
function                                             old     new   delta
static.neutral_b                                       -     320    +320
static.neutral_p                                       -     142    +142
unicode_bidi_isrtl                                     -      55     +55
unicode_bidi_is_neutral_wchar                          -      55     +55
isrtl_str                                             51      59      +8
unicode_isrtl                                         55       -     -55
read_line_input                                     5003    4937     -66
------------------------------------------------------------------------------
(add/remove: 4/4 grow/shrink: 1/1 up/down: 580/-121)          Total: 459 bytes

Signed-off-by: Tomas Heinrich <heinrich.tomas@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/Config.in b/Config.in
index e0c01f3..4439ce4 100644
--- a/Config.in
+++ b/Config.in
@@ -198,12 +198,23 @@
 
 config UNICODE_BIDI_SUPPORT
 	bool "Bidirectional character-aware line input"
-	default y
+	default n
 	depends on FEATURE_ASSUME_UNICODE && !LOCALE_SUPPORT
 	help
 	  With this option on, right-to-left Unicode characters
 	  are treated differently on input (e.g. cursor movement).
 
+config UNICODE_NEUTRAL_TABLE
+	bool "In bidi input, support non-ASCII neutral chars too"
+	default n
+	depends on UNICODE_BIDI_SUPPORT
+	help
+	  In most cases it's enough to treat only ASCII non-letters
+	  (i.e. punctuation, numbers and space) as characters
+	  with neutral directionality.
+	  With this option on, more extensive (and bigger) table
+	  of neutral chars will be used.
+
 config LONG_OPTS
 	bool "Support for --long-options"
 	default y