Keep content of messages if context is unencrypted

Fixes #65
Handle incoming irc ACTION in unencrypted message
Update tests for `html_escape` policy

The policy is only applied if we are actually in an encrypted context
Add SessionTestCase class for session tests.
Add infolist to WeeChat mock.

Also add commands and config_integer_default.
Add tests for log level restoration.
Add name and plugin to mock buffers.
Use buffer_get_string in get_logger_option_name.

Wrapper handles encoding.
Check for unset log level first in get_log_level.

Avoid searching infolist if possible.
Remove empty line.
Merge pull request #73 from tribut/modify-messages-unencrypted

Only modify message contents if the context is encrypted
Revert "Update tests for `html_escape` policy"

This reverts commit 0e04ebf6f5232bc305d28ab30a08ec3ae39667cb.
Tests for msg_convert_in/out when not encrypted.

Unit tests for #73.
Merge pull request #74 from tribut/unencrypted_action

Handle incoming irc ACTION in unencrypted message
Test for IRC ACTION in unencrypted message.
Use user-configurable prefix for output

Fixes #51
Colorize messages according to type
Remove default log level from message
Merge pull request #76 from tribut/logging-reset-default

Wrong message when resetting to default log level
Fix typo in debug message.