Fix __init__ "-" symbol issue

Solving "-" symbol can't be analyze issue . 

For example,
In keyword , chap-EX喬沛詩 , SK-II  ...etc 
the present version will show "chap", "-", "EX喬沛詩" , "SK", "-", "II"

After the modify,
The new version will show  "chap-EX","喬沛詩" , "SK-II" 

ps: I have used the jieba.load_userdict() , and added  "chap-EX" , "喬沛詩", "SK-II" in the userdict.txt.

jieba/__init__.py

@@ -40,7 +40,10 @@ re_eng = re.compile('[a-zA-Z0-9]', re.U)
 
 # \u4E00-\u9FD5a-zA-Z0-9+#&\._ : All non-space characters. Will be handled with re_han
 # \r\n|\s : whitespace characters. Will not be handled.
-re_han_default = re.compile("([\u4E00-\u9FD5a-zA-Z0-9+#&\._%]+)", re.U)
+# re_han_default = re.compile("([\u4E00-\u9FD5a-zA-Z0-9+#&\._%]+)", re.U)
+# Adding "-" symbol in re_han_default
+re_han_default = re.compile("([\u4E00-\u9FD5a-zA-Z0-9+#&\._%\-]+)", re.U)
+
 re_skip_default = re.compile("(\r\n|\s)", re.U)
 re_han_cut_all = re.compile("([\u4E00-\u9FD5]+)", re.U)
 re_skip_cut_all = re.compile("[^a-zA-Z0-9+#\n]", re.U)