New symbol: double_line: ═
New block symbols: upper_block_1: ▔,
upper_block_4: ▀, lower_block_1: ▁, etc.
lower_block_8: █ (lower_block_8 is also known
as full_block.)
Better detection of UTF-8 support: use the official
l10n_info() function
Three more symbols: neq: ≠, geq: ≥,
leq: ≤
First released version.