delay the discovery of sensors after powerup

Calling ow_periodic() from onewire_init() only works when
DEBUG_OW_POLLING is enabled. OW_DEBUG_POLL inside ow_periodic()
delays the discovery for some time and the discovery then works.
Without DEBUG_OW_POLLING, the discovery is not being delayed and
fails for some reason.
To solve this, ow_periodic() will be first called after 50*20ms = 1s.

Signed-off-by: Maximilian Güntner <maximilian.guentner@gmail.com>
Changed Makefile to use bash from homebrew on Mac OS X

Homebrew (http://mxcl.github.io/homebrew/) is an alternative to
MacPorts, it installs all binaries in /usr/local/bin
Added *.dSYM to gitignore

These are automatically generated on Mac OS X
make tftp work when TFTP_CRC_SUPPORT is enabled and no format string is given.
added hardware description files for antares boards.
make faster bootloader heartbeat working
added rejecting code to while loop.
Merge pull request #217 from neffs/master

small changes for Mac OS X
Merge pull request #218 from sauttefk/e6-upstream2

make tftp work when TFTP_CRC_SUPPORT is enabled and no format string is ...
Merge branch 'master', remote-tracking branch 'origin'
Merge remote-tracking branch 'upstream/master'
Merge pull request #213 from mguentner/1w-discovery-fix

delay the discovery of sensors after powerup
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'origin/master' into project_neptun