Unicode support for strings

Add suport for using unicode strings in .scad files. Support iterating
across them/accessing them via [] and searching.
--------
Add GLIB (to build for test and normal build -- both with installed and
built locally development files).
Add support for unicode chars to length and search builtin functions and
[] for strings.
Added unicode testing functions.
Ad GLIB to library info page.

1 files changed, 104 insertions, 0 deletions

diff --git a/tests/regression/echotest/string-unicode-expected.echo b/tests/regression/echotest/string-unicode-expected.echo
new file mode 100644
index 0000000..b4b848f
--- /dev/null
+++ b/tests/regression/echotest/string-unicode-expected.echo
@@ -0,0 +1,104 @@
+ECHO: "[", 0, "] = ", "DEADBEEF", " of len=", 8, ":"
+ECHO: "    [", 0, "]=", "D"
+ECHO: "    [", 1, "]=", "E"
+ECHO: "    [", 2, "]=", "A"
+ECHO: "    [", 3, "]=", "D"
+ECHO: "    [", 4, "]=", "B"
+ECHO: "    [", 5, "]=", "E"
+ECHO: "    [", 6, "]=", "E"
+ECHO: "    [", 7, "]=", "F"
+ECHO: "[", 1, "] = ", "Ленивый рыжий кот", " of len=", 17, ":"
+ECHO: "    [", 0, "]=", "Л"
+ECHO: "    [", 1, "]=", "е"
+ECHO: "    [", 2, "]=", "н"
+ECHO: "    [", 3, "]=", "и"
+ECHO: "    [", 4, "]=", "в"
+ECHO: "    [", 5, "]=", "ы"
+ECHO: "    [", 6, "]=", "й"
+ECHO: "    [", 7, "]=", " "
+ECHO: "    [", 8, "]=", "р"
+ECHO: "    [", 9, "]=", "ы"
+ECHO: "    [", 10, "]=", "ж"
+ECHO: "    [", 11, "]=", "и"
+ECHO: "    [", 12, "]=", "й"
+ECHO: "    [", 13, "]=", " "
+ECHO: "    [", 14, "]=", "к"
+ECHO: "    [", 15, "]=", "о"
+ECHO: "    [", 16, "]=", "т"
+ECHO: "[", 2, "] = ", "كسول الزنجبيل القط", " of len=", 18, ":"
+ECHO: "    [", 0, "]=", "ك"
+ECHO: "    [", 1, "]=", "س"
+ECHO: "    [", 2, "]=", "و"
+ECHO: "    [", 3, "]=", "ل"
+ECHO: "    [", 4, "]=", " "
+ECHO: "    [", 5, "]=", "ا"
+ECHO: "    [", 6, "]=", "ل"
+ECHO: "    [", 7, "]=", "ز"
+ECHO: "    [", 8, "]=", "ن"
+ECHO: "    [", 9, "]=", "ج"
+ECHO: "    [", 10, "]=", "ب"
+ECHO: "    [", 11, "]=", "ي"
+ECHO: "    [", 12, "]=", "ل"
+ECHO: "    [", 13, "]=", " "
+ECHO: "    [", 14, "]=", "ا"
+ECHO: "    [", 15, "]=", "ل"
+ECHO: "    [", 16, "]=", "ق"
+ECHO: "    [", 17, "]=", "ط"
+ECHO: "[", 3, "] = ", "懶惰的姜貓", " of len=", 5, ":"
+ECHO: "    [", 0, "]=", "懶"
+ECHO: "    [", 1, "]=", "惰"
+ECHO: "    [", 2, "]=", "的"
+ECHO: "    [", 3, "]=", "姜"
+ECHO: "    [", 4, "]=", "貓"
+ECHO: "[", 4, "] = ", "äöü ÄÖÜ ß", " of len=", 9, ":"
+ECHO: "    [", 0, "]=", "ä"
+ECHO: "    [", 1, "]=", "ö"
+ECHO: "    [", 2, "]=", "ü"
+ECHO: "    [", 3, "]=", " "
+ECHO: "    [", 4, "]=", "Ä"
+ECHO: "    [", 5, "]=", "Ö"
+ECHO: "    [", 6, "]=", "Ü"
+ECHO: "    [", 7, "]=", " "
+ECHO: "    [", 8, "]=", "ß"
+ECHO: "[", 5, "] = ", "😁😂😃😄😅😆😇😈😉😊😋😌😍😎😏😐", " of len=", 16, ":"
+ECHO: "    [", 0, "]=", "😁"
+ECHO: "    [", 1, "]=", "😂"
+ECHO: "    [", 2, "]=", "😃"
+ECHO: "    [", 3, "]=", "😄"
+ECHO: "    [", 4, "]=", "😅"
+ECHO: "    [", 5, "]=", "😆"
+ECHO: "    [", 6, "]=", "😇"
+ECHO: "    [", 7, "]=", "😈"
+ECHO: "    [", 8, "]=", "😉"
+ECHO: "    [", 9, "]=", "😊"
+ECHO: "    [", 10, "]=", "😋"
+ECHO: "    [", 11, "]=", "😌"
+ECHO: "    [", 12, "]=", "😍"
+ECHO: "    [", 13, "]=", "😎"
+ECHO: "    [", 14, "]=", "😏"
+ECHO: "    [", 15, "]=", "😐"
+ECHO: "[", 6, "] = ", "⠁⠂⠃⠄⠅⠆⠇⠈⠉⠊⠋⠌⠍⠎⠏", " of len=", 15, ":"
+ECHO: "    [", 0, "]=", "⠁"
+ECHO: "    [", 1, "]=", "⠂"
+ECHO: "    [", 2, "]=", "⠃"
+ECHO: "    [", 3, "]=", "⠄"
+ECHO: "    [", 4, "]=", "⠅"
+ECHO: "    [", 5, "]=", "⠆"
+ECHO: "    [", 6, "]=", "⠇"
+ECHO: "    [", 7, "]=", "⠈"
+ECHO: "    [", 8, "]=", "⠉"
+ECHO: "    [", 9, "]=", "⠊"
+ECHO: "    [", 10, "]=", "⠋"
+ECHO: "    [", 11, "]=", "⠌"
+ECHO: "    [", 12, "]=", "⠍"
+ECHO: "    [", 13, "]=", "⠎"
+ECHO: "    [", 14, "]=", "⠏"
+ECHO: "[", 7, "] = ", "🂡🂱🃁🃑", " of len=", 4, ":"
+ECHO: "    [", 0, "]=", "🂡"
+ECHO: "    [", 1, "]=", "🂱"
+ECHO: "    [", 2, "]=", "🃁"
+ECHO: "    [", 3, "]=", "🃑"
+ECHO: "Past end of unicode only 2-byte ", undef
+ECHO: "Past end of unicode only 4-byte ", undef
+ECHO: "Past end of both 2-byte ", undef
+ECHO: "Past end of both 4-byte ", undef