Add the Binary data type and corresponding helper functions to Asterix.

The binary data type is implemented as a bytearray. Its storage format
follows the String type which has 2 bytes for length and then store the
bytes contents.

Binary data will take hex("") or base64("") as the constructor method to
passing a hex string or base64 string into Asterix. For output we use
hex("") format.

The parse-[hex|base64](string) function will parse the corresponding hex
or base64 string to binary type. The print-[hex|base64](binary)
functions will print the binary to hex or base64 STRING format.

The sub-binary(binary, offset, [length]) function works the same as
substring(string, offset, [length])
The find-binary(srcbinary, targetbinary, [start-offset]) will find the
position of the targetbinary in the srcbinary.

Change-Id: I5ecf0cc115c44070fb5c1fc5b0ec12a95d4243a4
Reviewed-on: http://fulliautomatix.ics.uci.edu:8443/175
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Yingyi Bu <buyingyi@gmail.com>
diff --git a/.gitignore b/.gitignore
index 39d2528..189af35 100644
--- a/.gitignore
+++ b/.gitignore
@@ -19,5 +19,6 @@
 *-coredump
 *.pyc
 *.iml
+.idea/
 asterix.ipr
 asterix.iws