Fix multiline input

[kainonergon]

Lemonbar has a bug, that it only reads the first line from input, if lines come fast, for example:

{echo a; echo b} | lemonbar -p

will show "a" and not "b". See
LemonBoy#107

This fix makes lemonbar read all lines from input and show the last one. It is taken from here:
LemonBoy@309047f

[krypt-n]

Thanks for the PR. Have you tested this a) with your minimal example and b) with a reasonably complex input?

[kainonergon]

Yes, I've tested it. That minimal example shows last line of input as expected. Also I use version of lemonbar-xft with this patch from my fork on daily basis for about a month. I have this panel script with lemonbar so I guess it is complex enough. Works much better with this patch, I don't have to add delays as a workaround for this bug.

EDIT. Only the first commit is needed. Other three were my unsuccessful attempt to fix transparency with xft, so I reverted all changes
EDIT 2. I've squashed all commits into one.

[kainonergon]

This patch also makes lemonbar much faster when it gets a lot of lines without delay. For example here are results from this bash command with the patch:

$ time printf "%s\n" {1..999999}|lemonbar

real	0m1.469s
user	0m0.983s
sys	0m1.271s

and without the patch:

$ time printf "%s\n" {1..999999}|lemonbar

real	1m33.811s
user	0m5.744s
sys	0m5.020s

[cpence]

For anyone else who shows up confused to this issue, this can cause a problem with some ways of running your lemonbar contents script. If you were previously building your bar with:

echo -ne 'part 1'
echo -ne 'part 2'
...
echo ''

then your bar will no longer work after this patch. You should build your bar contents in a variable and echo them once:

line=''
line+='part 1'
line+='part 2'
...
echo -e $line

No idea why this commit would have caused that, but that's how you fix it.