Remove support for the old '-' escape

It hasn't worked for almost two years now.

Author: FichteFoll

Package/CSScheme.YAML-tmLanguage

@@ -45,7 +45,6 @@ repository:
     - include: '#selector-patterns'
 
   selector-patterns:
-    # all backslash-escape variants are for the SASS pre-processor
     patterns:
     - include: '#selector-operators'
     - name: constant.language.wildcard.csscheme  # our special "settings" selector
@@ -58,9 +57,10 @@ repository:
       match: '.'
 
   selector-operators:
+    # all backslash-escape variants are for the SASS pre-processor
     patterns:
     - name: keyword.operator.subtraction.csscheme
-      match: -|'-'|\\-  # '-' is an escape for the SASS pre-processor
+      match: -|\\-
     - name: keyword.operator.intersection.csscheme
       match: '&|\\&'
     - name: keyword.operator.union.csscheme

Package/CSScheme.tmLanguage

@@ -376,7 +376,7 @@
 			<array>
 				<dict>
 					<key>match</key>
-					<string>-|'-'|\\-</string>
+					<string>-|\\-</string>
 					<key>name</key>
 					<string>keyword.operator.subtraction.csscheme</string>
 				</dict>

Package/SCSScheme.YAML-tmLanguage

@@ -256,9 +256,10 @@ repository:
       match: '.'
 
   selector_operators:
+    # all backslash-escape variants are for the SASS pre-processor
     patterns:
     - name: keyword.operator.subtraction.csscheme
-      match: -|'-'|\\-  # '-' and \\- are escapes for the SASS pre-processor
+      match: -|\\-
     - name: keyword.operator.intersection.csscheme
       match: '\\&'
     - name: keyword.operator.union.csscheme

Package/SCSScheme.tmLanguage

@@ -1258,7 +1258,7 @@
 			<array>
 				<dict>
 					<key>match</key>
-					<string>-|'-'|\\-</string>
+					<string>-|\\-</string>
 					<key>name</key>
 					<string>keyword.operator.subtraction.csscheme</string>
 				</dict>

tinycsscheme/dumper.py

@@ -146,9 +146,6 @@ def datafy_ruleset(self, rset):
             # Notably, this allows "numeric classes"
             # and all operators (including braces).
             sel = sel.replace("\\", "")
-            # '-' was used initially for only the subtract operator
-            # but is not recognized anymore starting around Dec 2014.
-            sel = sel.replace("'-'", "-")
             # Also replace multiple whitespaces (including newlines)
             # with a single space;
             # we don't know how exactly it will perform otherwise.