Classes.cpp: Refactoring.
SecureShell.cpp: Refactoring; TSecureShell::Receive: Fix warning.
Sysutils.cpp: Fix warning.
GetFiles --> GetFile
Fix minor warnings.
Fix code style.
Fix minor warnings.
WebDAVFileSystem.cpp: Some optimizations.
WebDAV: Try to optimize.
WebDAV: Try to fix error: "Connection timeout" after large file is copied to WebDAV server.
ne_socket.c: Add SO_KEEPALIVE