Merge pull request janluke#169 from pocek/fix-help-truncation

Truncate help text to the first form feed, like click

Merge pull request janluke#167 from janluke/fix/constraint-cannot-be-…

…copied

Fix: `Constraint.__getattr__` was returning `None` instead of raising `AttributeError`

Merge pull request janluke#163 from janluke/helptheme-as-dataclass

`HelpTheme` as `dataclass` rather than `NamedTuple`

Merge pull request janluke#162 from janluke/fix/group_command_and_gro…

…up_class

Fix: default to `Group.command_class` and `Group.group_class` when creating subcommands

Merge pull request janluke#158 from janluke/fix/write_usage

Fix `write usage`: formatting and default value

Add alias_secondary to HelpTheme docstring

Update issue templates

Remove unused import from setup.py

Merge pull request janluke#130 from janluke/fix/skip-constraints-if-help

Skip constraints checking when `--help` is passed

Update CHANGELOG.rst for release v1.0.1