unicode_width.h: rename to use dash in file name

This is more consistent with the project style. The majority of Git's
source files use dashes in preference to underscores in their file names.

Also adjust contrib/update-unicode as well.

Signed-off-by: Stefan Beller <sbeller@google.com>
diff --git a/contrib/update-unicode/README b/contrib/update-unicode/README
index b9e2fc8..151a197 100644
--- a/contrib/update-unicode/README
+++ b/contrib/update-unicode/README
@@ -1,10 +1,10 @@
 TL;DR: Run update_unicode.sh after the publication of a new Unicode
-standard and commit the resulting unicode_widths.h file.
+standard and commit the resulting unicode-widths.h file.
 
 The long version
 ================
 
-The Git source code ships the file unicode_widths.h which contains
+The Git source code ships the file unicode-widths.h which contains
 tables of zero and double width Unicode code points, respectively.
 These tables are generated using update_unicode.sh in this directory.
 update_unicode.sh itself uses a third-party tool, uniset, to query two
@@ -16,5 +16,5 @@
 
 On each run, update_unicode.sh checks whether more recent Unicode data
 files are available from the Unicode consortium, and rebuilds the header
-unicode_widths.h with the new data. The new header can then be
+unicode-widths.h with the new data. The new header can then be
 committed.
diff --git a/contrib/update-unicode/update_unicode.sh b/contrib/update-unicode/update_unicode.sh
index e05db92..aa90865 100755
--- a/contrib/update-unicode/update_unicode.sh
+++ b/contrib/update-unicode/update_unicode.sh
@@ -6,7 +6,7 @@
 #Cf Format          a format control character
 #
 cd "$(dirname "$0")"
-UNICODEWIDTH_H=$(git rev-parse --show-toplevel)/unicode_width.h
+UNICODEWIDTH_H=$(git rev-parse --show-toplevel)/unicode-width.h
 
 wget -N http://www.unicode.org/Public/UCD/latest/ucd/UnicodeData.txt \
 	http://www.unicode.org/Public/UCD/latest/ucd/EastAsianWidth.txt &&
diff --git a/unicode_width.h b/unicode-width.h
similarity index 100%
rename from unicode_width.h
rename to unicode-width.h
diff --git a/utf8.c b/utf8.c
index 2c27ce0..4419055 100644
--- a/utf8.c
+++ b/utf8.c
@@ -81,7 +81,7 @@ static int git_wcwidth(ucs_char_t ch)
 	/*
 	 * Sorted list of non-overlapping intervals of non-spacing characters,
 	 */
-#include "unicode_width.h"
+#include "unicode-width.h"
 
 	/* test for 8-bit control characters */
 	if (ch == 0)