Bug 615: Removed xtend from Topology Manager

Rewriten Topology Exporter to Java code, added synchronized blocks
to critical pieces of code, which created conflicting transactions

Change-Id: I8d9cad2e0f6edfd2440d134ec0e2b670c16470b4
Signed-off-by: Tony Tkacik <ttkacik@cisco.com>
Signed-off-by: Robert Varga <rovarga@cisco.com>
BUG-731: do not catch Throwable

This fixes the bad practice of catching Throwable, and uses logger
instead of e.printStackTrace().

Change-Id: I44541f7c71dda0bcf633d22d9a46b3959ed3001f
Signed-off-by: Robert Varga <rovarga@cisco.com>
BUG-731: do not do String.toString()

Fixes a sonar warning. Also adds missing copyright headers.

Change-Id: If16eebc39e7f0d7e9787529995b666f04d239cdf
Signed-off-by: Robert Varga <rovarga@cisco.com>
BUG-731: remove unneeded null check

Fixes a sonar warning:
https://sonar.opendaylight.org/issue/show/0b9faac8-cbfc-4aed-8749-80fdd53410d5

Change-Id: Ib44157dde70d9c654f6dcb242e1d44619a685ea6
Signed-off-by: Robert Varga <rovarga@cisco.com>
Merge "Bug 615: Removed xtend from Topology Manager"
Merge "BUG-731: do not catch Throwable"
Merge "BUG-731: do not do String.toString()"
Merge "BUG-731: remove unneeded null check"