Move invalidTag assertion to correct place in Deduper::store().
Pass EPOLL_CLOEXEC to epoll_create1() in selector.hxx.
Fix "mark selection, scroll, drag selection" bug.
Added assertion to Widget::terminalDrawFg().
Remove defunct 'explicit'.
Implemented audible-bell-volume (percent) config option.
s/GenericSet/BitSet/g
Assert that bit shifts in BitSet don't cause overflow.
s/stdint.h/cstdint/g
Documentation updates in buffer.hxx.
Added isLead() and isCont() to utf8.
Use std::numeric_limits<Tag>::max() for invalid Tag.
Fix used/unused includes.
Use std::unique_ptr() in terminols.cxx.
Implement more of Regex class.
Move definition of selection methods from buffer.hxx to buffer.cxx.

Conflicts:
	terminol/common/buffer.hxx
Fixes #9. Implemented Buffer::ParaIter.

This fixes a long-standing bug in multi-click select where paragraphs
in the active region were not fully selected.