removeDuplicateEmptyLines

string txt =
	"\nvoid foo()\n"
	~ "{\n"
	~ "    if(1)\n"
	~ "\tx = 0;\n"
	~ "}";
string exp =
	"\n    void foo()\n"
	~ "    {\n"
	~ "\tif(1)\n"
	~ "\t    x = 0;\n"
	~ "    }";

string res = reindent(txt, 4, 8);
assume(res == exp);