tzselect: Removed spaces in calls to awk-functions

Explanation:
GNU awk fails when a user-defined-functions is called with a space like in
'myUDF ()'. It does not fail when calling builtin functions, but removed
those spaces too.

Example code:
good_awk='function echo(x) { return x; } BEGIN { print echo("x"); }'
bad_awk_='function echo(x) { return x; } BEGIN { print echo ("x"); }'
sin_awk='BEGIN { print sin (0) }'

mawk -W version 2>/dev/null | head -n1
mawk "${sin_awk}"
mawk "${good_awk}"
mawk "${bad_awk_}"
gawk -V | head -n1
gawk "${sin_awk}"
gawk "${good_awk}"
gawk "${bad_awk_}"

Output:
mawk 1.3.4 20141027
0
x
x
GNU Awk 4.0.2
0
x
gawk: cmd. line:1: error: function `echo' called with space between name
and `(',
* NEWS: Document POSIX awk fixes.