apps/builtin/exec_builtin.c: Try posix_spawn if builtin apps do not have have an entry point.
apps/Application.mk: introduce MODULE config to simplify tristate(m)
apps/nsh: Change the nuttx shell module type to tristate
apps: Add loadable application support
script/mksymtab: Generate symbol table name by default
apps/builtin: Allow loadable applications can register with apps/builtin.
apps/examples/tcpblaster: Some improvements/fixes in statistics reporting.
apps/examples/tcpblaster: Add performance measurement functionality.
apps/examples/tcpblaster: Initial commit is just apps/examples/nettest/ with naming changes.
