Before, lower_only was not being correctly set and was only considering
whether the string ended with a lowercase sequence. Refactored this with
some more explicit functions as the logic is a little confusing.
This adds tab completion to textinput components. They can be configured
with a completion function. This function is called when the user
presses <tab>. The first completion is initially shown to the user
inserted into the text. Repeated presses of <tab> or <backtab> cycle
through the completions list. The completions list is invalidated when
any other non-tab-like key is pressed.
Also changed is some logic for current completion generation so that
all available commands are returned when <tab> is pressed with no
current text and similarly for arguments of commands.
This patch sets up the trigger config section of aerc.conf.
Each trigger has its own function which is called from the place where
it is triggered. Currently only the new-email trigger is implemented.
The triggers make use of format strings. For instance, in the new-email
trigger this allows the user to select the trigger command and also the
information extracted from the command and placed into their command.
To actually execute the trigger commands the keypresses are simulated.
Further triggers can be implemented in the future.
Formatting of the command is moved to a new package.
