devSpec: allow backslash escaped whitespace in STRING tokens

This allows us to use spaces when specifying window name selectors.
Which is very convenient and cool.

hcore/deviceManager/deviceSpecl.ll

@@ -2,6 +2,8 @@
 %option nounput
 %{
 #include <vector>
+#include <string>
+#include <algorithm>
 #include <deviceManager/deviceManager.h>
 #include "deviceSpecp.hh"
 %}
@@ -24,7 +26,12 @@
 "("             { return LPAREN; }
 ")"             { return RPAREN; }
 [ \t]*"="[ \t]* { return EQUALS; }  // Allow optional whitespace around equals
-[^=\|\(\) \t\r\n]+ { deviceSpecplval.str = strdup(yytext); return STRING; }  // Exclude = from STRING tokens
+([^=\|\(\) \t\r\n]|\\[ \t])+ {
+    std::string token(yytext);
+    token.erase(std::remove(token.begin(), token.end(), '\\'), token.end());
+    deviceSpecplval.str = strdup(token.c_str());
+    return STRING;
+}
 \r?\n           { /* ignore newlines */ }
 [ \t]+          { /* ignore whitespace */ }
 .               { return yytext[0]; }