convert longnames to unicode
permit all letters in symbol names
enable entering characters by hex/oct codes
add simple tests for new character input modes
decode utf-8 byte strings to allow unicode characters in parser input
add aliased_characters dict to core.characters
implement letterlike pattern and allow letterlikes in symbol names
add tests for letter-like forms in symbols
decode shell input using sys.stdin.encoding
temp hack to escape \[DifferentialD] for TeXForm
Merge pull request #128 from sn6uv/UnicodeCharacters

Unicode characters