is in accordance with the information provided at
ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
Also add $FreeBSD$ to a few files to keep svn happy.
Discussed with: imp, rwatson
- Exit if getch() returns with an error other than EINTR. Otherwise
systat(1) may get stuck in an infinite loop if it doesn't receive
SIGHUP when terminal closes. [1]
- Remove attempt to clear stdio error indicators. getch() doesn't use
stdio, making it useless. [2]
- Remove unneeded masking of getch() return value. [2]
PR: bin/107171
Reviewed by: bde
Approved by: trasz (mentor)
Obtained from: OpenBSD [1]
Suggested by: bde [2]
MFC after: 1 month
