Fix man page and usage()

Man page was repeating -f option, the second time instead of -i,
and this option was lost in usage() message. This patch also indent
the output of usage().
Simplify README

The term 'virtual terminal emulator' was broken. There is nothing
virtual about it, it's a terminal emulator.

Signed-off-by: Alexander Huemer <alexander.huemer@xx.vu>
Signed-off-by: Roberto E. Vargas Caballero <k0ga@shike2.com>
simplify loop in tresize

Signed-off-by: Roberto E. Vargas Caballero <k0ga@shike2.com>
reset the alt screen in treset

Signed-off-by: Roberto E. Vargas Caballero <k0ga@shike2.com>
Make useful DEL in application mode

DEL key has to generate the sequence ^[P in application mode,
because such sequence means delete current character. It implies
that the character sent in keypad mode must be ^? (DEL character).
Fix definition of CONTROLC0

DEL character is not thecnically talking a C0 control character,
although it has some common properties with them, so it is useful
for us consider it as C0. Before this patch DEL (\177), was not
ignored as it ought to be.
Improve execsh() and don't allow anonymous shells

This patch improves the shell selection on execsh and forbid
shell with users don't registered in the passwd file.
Add eschandle()

We already have a csihandle() function, where is located code about
CSI sequences, so it is logical do the same with ESC sequences.
This change helps to simplify tcontrol(), which has a complex flow
and should be rewritten.
Improve readability of enum members

The 'left shift from one' notation of power of two integers is more
expressive than the result.

Signed-off-by: Alexander Huemer <alexander.huemer@xx.vu>
Signed-off-by: Roberto E. Vargas Caballero <k0ga@shike2.com>
Move calls to selsnap into selnormalize

This simplifies getbuttoninfo() and bpress(), and fixes a bug which made word
snapping behave incorrectly when a delimiter was at the beginning or end of
line.

Signed-off-by: Roberto E. Vargas Caballero <k0ga@shike2.com>
Change the behavior of word snapping on delimiters

This makes any sequence of identical delimiters be considered a single
word in word-snapping mode. This seems more coherent for this mode and
is similar to what xterm does.

Signed-off-by: Roberto E. Vargas Caballero <k0ga@shike2.com>
Removing wrapping newlines from selection

When getting selected text, lines that were wrapped because of length
ought not include the wrapping newline in the selection.

This comes up, for example, when copying a bash command that is long
enough to wrap from the console and pasting it back into the console.
The extra newline breaks it.

Similiarly, changes behavior when trimming whitespace from the end of a
physical line to only do so if the line does not wrap. Otherwise we are
trimming whitespace from the middle of a logical line, which may change
its meaning.

Signed-off-by: Roberto E. Vargas Caballero <k0ga@shike2.com>
Remove indentation level in xdrawcursor
Add support for utmp in st

St runs an interactive shell and not a login shell, and it means
that profile is not loaded. The default terminal configuration
in some system is not the correct for st, but since profile is
not loaded there is no way of getting a script configures the
correct values.

St doesn't update the utmp files, this is the job of another
suckless tool, utmp. Utmp also opens a login shell (it is the
logical behaviour when you create a new user record) it is a
good option execute utmp and then get a correct input in
utmp, wtmp and lastlog file, and execute the content of the
profile.
Add missed names of charset sequences
Implementing xzoomreset.

Thanks mvdan@mvdan.cc for proposing this.
Minor style changes for the last patch.
Removing an extra space.
Fix SI and SO

SI (0x0F or ^O) means Shift In, and it selects G1 charset definition,
and SO (0x0E or ^N) means Shift Out, and it selects G0 charset
definition, but st was doing just the inverse.
Add LS2 and LS3

These sequences are the equivalents of LS0 and LS1, but for G2 and
G3.