fix PageUp Modifier Mask in config.def.h

Signed-off-by: Christoph Lohmann <20h@r-36.net>
Fix selection clearing

The way st knows if there is a selection activated is checking if sel.ob.x
is equal to -1. In some parts of the code the way of disabling the selection
was only setting it to -1, but after it you can't be sure if the selection
is clearing from the terminal representation, because it is necessary mark
all the lines affected by the selection as dirty. Already there is a functon
which perform this task, selclear.
Remove unneded call to draw

draw is the function which update the Xwindow with the information st has,
and it is designed in a way that it must be called once in the main loop
(run function), and calling it in other places it is a waste of time.
Fix match function bugs

There were two problems with match denfinition.

1) There was a forward declaration in the form:

	static inline bool match(uint, uint);

but later the function was defined as:

	inline bool
	match(uint mask, uint state) {

This causes that there were two different functions in the code, one local
and inline, and other inline but extern. All was working without problems
due to we were using -Os, and the compiler was using the extern definition
and it was no expanding the static declaration. If you removed the -Os flag,
then you got linker errors due it was no able to find the static definition
of the static declaration.

2) The mask checking was incorrect because we were doing the test:

	(state & mask) != state

and this test only was saying that at least all the enabled bits of state
were enabled also in mask, but no all the possible bits in mask. This was
the origin of the bug reported by Xavier Cartron, where he said it was
possible activated some shortcuts with some of the modifiers defined in the
config.h file.
fix: do not need an extra variable for a single read
fix: consistent usage of bitmask operations on unicode functions
Remove long text being cropped/wrapped to standard 80x24 on launch.

To be more specific, now tty creation is delayed until X window is
actually mapped; last ConfigureNotify before mapping determines
initial tty size.
Please report problems if there are any.
fix: whitespace