Merge branch 'expander-methods' into 'master'

src/lib/builtins/variables.rs

src/lib/parser/assignments/checker.rs

src/lib/parser/loops.rs

src/lib/parser/mod.rs

src/lib/parser/pipelines/mod.rs

src/lib/parser/shell_expand/mod.rs

src/lib/parser/shell_expand/words/methods/arrays.rs

src/lib/parser/shell_expand/words/methods/mod.rs

src/lib/parser/shell_expand/words/methods/strings.rs

src/lib/parser/shell_expand/words/mod.rs

src/lib/shell/binary/prompt.rs

src/lib/shell/flow.rs

src/lib/shell/job.rs

src/lib/shell/variables/mod.rs