v0.42.0

Most relevant commits:

• compiler/parser: fix missing error for non-declaration in {%% ... %%}
• templates/builtin: add formatFloat, formatInt, parseFloat and parseInt
• runtime, compiler: simplify Move instruction removing explicit 'copy'
• compiler/disassembler: fix disassembling of OpField and OpSetField
• compiler/emitter: fix size of composite literal map
• runtime, compiler: extend max number constants count from 256 to 16384
• compiler: implement 'show' with expression list
• compiler/disassembler: don't disassemble type for LoadNumber instruction
• compiler, runtime: extend 'LoadNumber' and rename it to 'Load'
• compiler/checker: fix panic using predeclared identifier nil in selector
• compiler/checker: fix error message on invalid pointer indirection
• runtime: fix error accessing a field of a nil embedded struct
• compiler/disassembler: disassemble field index without brackets
• runtime: handle errors in the '-SetField' instruction
• compiler: fix assignment to field selectors with pointer types
• runtime: remove 'FieldRef' instruction