Update Go for 1.13 and fix bugs
- Made package and import externals, like in Java
- Fixed escape characters: Go octal escapes take exactly three digits; hex escapes take exactly two digits; added Unicode escape sequences
- Added the printf verbs %O and %F plus support the 1-indexing of arguments within fmt e.g. %[1]d
- Added support for Go 1.13's new integer literal syntaxes: 0b for binary, 0o/0O for octal, hex floating point literals like 0x1.fp-2, underscores between digits, and the imaginary suffix i which can now attach to any literal
All syntaxes tested and working on my Ubuntu 18.04 machine with libgtksourceview 3.24.7-1 and gedit 3.28.1.
Fixes #75 (closed)