support for rlt-1600g-w and rlt-1600x-w in GPON mode

Change-Id: Ib230d3e336043980eb00427384a49cb8bd386bb2

VOL-4151: Code improvement to use static const instead of static
to allow for compiler optimization.
Also fixed SECURITY.md document as the sample commands were not
ready for copy/paste earlier.

Change-Id: I7fdfa03ed3e6677466fb78b8ea8532d4f5c0a6da

Changes made to upgrade BAL from 3.4.9.8 to 3.4.9.9 for rlt-1600g/x-w and rlt-3200g-w

Change-Id: I2baa09074a43703b7ca22625592d28b03863a06c

VOL-4268: Migration to BAL3.4.9.9 for voltha master and 2.8 branch

Change-Id: I66c77149524f2592fb018a3bc00dc9c8a8f94153
diff --git a/.gitignore b/.gitignore
index 56dc8a3..5200942 100644
--- a/.gitignore
+++ b/.gitignore
@@ -44,3 +44,6 @@
 agent/src/read_rxtx_power
 agent/read_rxtx_power
 eeprom.bin
+
+# downloaded Accton patch files and BAL packages
+agent/download/*