Make quickfind interruptible.

Fixes #60

Merge pull request #165 from variar/fix_mouse_button_check

Fix mouse button check

Merge pull request #167 from variar/ignore_case_fix

Use clicked signal instead of toggled

Use clicked signal instead of toggled

Fix mouse button check

Fix compiler warnings

Remove connect to followDisabled (no such slot)

Add some Qt-specific files to .gitignore

Clang-format style file

Remove support for 'Wildcard' searches.

Thy are untested and probably not used much.
Also fix a bug in QRegularExpression implementation of QuickFind.

Switch from deprecated QRegExp to QRegularExpression

Add support for CP1251 and CP1252.

Show null characters as spaces.

Re-work position calculation to display UTF-16 properly.

Add automatic support for UTF16.

Fix and end of line bug when a line is extended on a block (256) boundary.

Add initial support for UTF-16.

Switch to Qt 5.8.0 for Mac builds, fixing a high CPU usage problem.

Add shortcuts 'v', '+' and '-' to manipulate filtered view size and content.

Fixes #156

Add [space] and 'm' shortcuts to switch view and set/unset a mark.

Allow [ and ] to move to next/prev mark.

Fixes #140

Ensure debug symbols are generated on macOS.

When doing a partial index, detect the start point in the worker thread.

It used to be done in the main thread and mangled the index in some
cases.

Fixes #149.

Change comment and desktop file to support opening multiple files.

Merge remote-tracking branch 'variar/f_open_several_files'