Fix Solaris support

Fix and simplify the Solaris support.
Remove golang.org/x/sys/unix dependency for Solaris.
Add new build tags format.

Add support for NetBSD and LoongArch

Add support for NetBSD and LoongArch

Add arm support for OpenBSD

Add openbsd archs

Signed-off-by: Guillaume J. Charmes <[email protected]>

Fix CTTY to work with go1.15

Use stdin as the controlling terminal by default instead of setting it to the parent TTY.

v1.1.9: Bump go 1.13

Signed-off-by: Guillaume J. Charmes <[email protected]>

Add more os/arch support

Add support for linux/solaris linux/riscv linux/riscv64

Set Ctty in SysProcAttr

Required fix to work with go1.13

Allow preset i/o in StartWithSize

Don't set Stdin/Stdout/Stderr if already set (#71)

* only set stdout and stderr if not already set

* Don't set cmd.Stdin if it's already set

Considered @craek's codereview

Add StartWithSize

Add StartWithSize to allow resizing pty before starting a command to avoid races

OpenBSD 32bits

Add support for 32bits OpenBSD.