Add RGB color definition

This patch uses the bit 24 in the color descriptor as an indicator
of RGB color, so we can take the values and generating the XftColour
directly in xdraws.
Reload colors in reset

Colors definition can be changed using a OSC sequence, so
we have to reload them if we want be sure all the colors
are the correct.

Could be desirable free the colors allocated due to rgb
colors and inverse colors (XftColorAllocValues in xdraws),
but it is impossible due we use the same structure for all
of them.
Use character size scaling factors

The bounding boxes for characters can be scaled using "cwscale" and "chscale"
to scale the width and height respectively.
Fix blink mode check

ATTR_BLINK is an attribute for a Glyph and will not be set in term.mode.
Fixed memory leak in xsettitle().
Fix signess of tdefcolor

tdefcolor() returns -1 on error, while its return type is
unsigned long. At the same time, line 1724 and 1731 are checking the
positivity of its unsigned return value.
Add terminfo definitions for terminals with meta key

Some programs don't check the value of km and use smm and rmm
capabilites, and they cause the terminal change to meta enabled
mode even in cases where is not desirable.

Allmost all people is using the terminal waiting that meta sends
escape, so rmm and smm are not needed. If someone needs meta
sets 8 bit he can use the correct terminfo definition in TERM.
Correcting the bitmask value check.
Tmux is using C-b by default.

Thanks for noticing Fidel Barrera Cruz!
Style
Die when display goes away
Merge remote-tracking branch 'origin/master' into wayland

Conflicts:
	st.c