Add U+201E to quotation marks and remove U+201B

U+201E (DOUBLE LOW-9 QUOTATION MARK, "„") has been removed along with
U+201F (DOUBLE HIGH-REVERSED-9 QUOTATION MARK, "‟") in
b05c913f. Yet, U+201F is not only the
correspending quote to U+201F but also to U+201C (LEFT DOUBLE QUOTATION
MARK, "“") in a couple of languages, including german[1]. As both
DroidSans and Roboto have a glyph for U+201E I have added it back.

I have removed U+201B (SINGLE HIGH-REVERSED-9 QUOTATION MARK, "‛"),
however, as U+2018 (LEFT SINGLE QUOTATION MARK, "‘") is the preferred
variant[2] (like U+201C, "LEFT DOUBLE QUOTATION MARK" (”), is to
U+201F[3]) and in fact the single-quote pendant to U+201F.

References:
1: https://en.wikipedia.org/wiki/Non-English_usage_of_quotation_marks
2: http://www.fileformat.info/info/unicode/char/2018/index.htm
3: http://www.fileformat.info/info/unicode/char/201c/index.htm

Change-Id: I9ffe1364ac1de2e568e1cdc1bd5dd48edd8db36c