src/parse_macros.h, src/server.c, src/erver_pty.c,
src/server_session.c, xalloc.c: Minor bugfixes, reported by David
Kågedal.

Rev: src/algorithms.h:1.6
Rev: src/channel.c:1.82
Rev: src/debug.h:1.14
Rev: src/parse_macros.h:1.2
Rev: src/server.c:1.63
Rev: src/server_pty.c:1.16
Rev: src/server_session.c:1.45
Rev: src/xalloc.c:1.23