Upgrade_Api_Only
 - Performs no upgrade of kernel before Api is upgraded, then checks Api behaviour

Upgrade_Api_Before_NR1
 - Same as Upgrade_Api_Only, followed by NR1 (Node by Node rolling restart)

Upgrade_Api_NDBD_MGMD
 - Upgrades Api first, then NDBD nodes (1 per ng at a time) then MGMD

Upgrade_Mixed_MGMD_API_NDBD
 - Upgrades MGMD, NDBD, API then MGMD + NDBD

Where the upgrade is not performed in the 'traditional' order, the postUpgrade
program is invoked with the noddl argument.  This is done as :
 1) 6.3 and 7.0 have specific DDL incompatibility due to schema transactions
    in 7.0
 2) In general (and enforced in 7.0), DDL should not be possible in a mixed
    version configuration.

New methods are added to NdbRestarter for querying running node versions.

Additionally some small test framework issues are fixed:
 - A constant for the parser max line length is provided.
 - CpcClient checks that arguments passed to CPCD are not larger than the 
   CPCD parser's maximum (512 bytes)
 - Set process environment part of Atrt modified to replace variables rather
   than append to the environment.
 - A small issue with Atrt mysql client reconnect is fixed