fixed CLOUDSTACK-6261: remove the forceful timeout setting when login to NetScaler.

(cherry picked from commit e07d0ddabfedad137856c3c9ae7de3a96fe25feb)
Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>

Conflicts:
	plugins/network-elements/netscaler/src/com/cloud/network/resource/NetscalerResource.java

(cherry picked from commit 5563a7314e4ec1d4dcc5674dfa831fd0328c06a9)

Conflicts:
	plugins/network-elements/netscaler/src/com/cloud/network/resource/NetscalerResource.java
CLOUDSTACK-7415. Host remains in Alert after vCenter restart.
Management server PingTask should update PingMap entry for an agent only if it is already present in the Management Server's PingMap.

(cherry picked from commit 8ce6eba549bcd3fa007aaf10a29c3a2fef9ffaaa)
Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
(cherry picked from commit 59ce63918e227f93d64642e881551c25738de3b3)