reuse tcp connections

tgsearch and tgcrud should keep tcp connections open for reuse (https://requests.readthedocs.io/en/latest/user/advanced/#session-objects)

assigned to @uveentj

created branch 87-reuse-tcp-connections to address this issue

mentioned in merge request !68 (merged)

testing performance like described in repdav#21 (comment 903677) (lots of tgsearch requests)

without c560c6ed

$ time ./listdir.sh
[...]
real	0m7,742s
user	0m0,009s
sys	0m0,013s


$ time ./listdir.sh
[...]
real	0m6,737s
user	0m0,012s
sys	0m0,014s

with c560c6ed

$ time ./listdir.sh
[...]
real	0m7,071s
user	0m0,014s
sys	0m0,008s

$ time ./listdir.sh
[...]
real	0m1,070s
user	0m0,006s
sys	0m0,010s

mentioned in commit 2ff4d3e4

closed with merge request !68 (merged)