TestGetProcInodesAll: create a server so there are some opened inodes
TestUsers: skip if Users is empty, because of an empty /var/run/utmp
Test_Process_Groups: skip if Groups is empty
TestConnectionsMax: skip on CI, not only CircleCI
The goal is to improve performance of connection fetching connections across
all processes when some processes can have several hundred or thousands of file
descriptors. Right now when you have many thousands of fds the process spends
lots of time inside the syscalls from Readdir and Readlink.
The public API works as before with two new functions:
- `ConnectionsMax`
- `ConnectionsPidMax`
Each function takes an additional int argument that sets the max number of fds
read per process.
