translator/lua: Add :(un)lockvar support
lua: Do not check locks when deleting key
lua: Adjust slice indicies computation for :lockvar

Will later be needed for slice :unlet
lua: Do not copy() locks
tests: Test how (deep)copy() preserves locks
tests: Test :lockvar
lua/tests: When deleting subscript check locks
lua/tests: Add support for :unlet’ting slices
translator/lua: Make curly braces names work
tests: Add tests for curly braces names
tests: Add :for loop tests
tests: Add :while loop test
translator: Add :break command support
tests: Add :break command tests
translator: Add :continue command support
tests: Add :continue command tests
parser: Fix glob parser function, add some code for :edit
printer/tests: Add some :edit tests, use glob AST when printing

Unless using glob AST it is impossible to distinguish between glob parsed as
shell call and glob parsed as a literal string.