let Item::clone() create a deep copy of the item tree

Product multiplexing uses Item::clone() to create a product item
per profile. Cloning the product is not enough, however.
We must create clones of the children and item properties too.

Task-number: QBS-690
Change-Id: I8f46488ffa5df255ee9c2b0571145c7ff034c204
Reviewed-by: Christian Kandeler <christian.kandeler@digia.com>
yield error on undefined elements in string lists

Instead of converting undefined values in string list properties
to the string "undefined", we yield an error.

Change-Id: Id370dafa67061f1f1a86bbeaaeed152be6fc751f
Reviewed-by: Christian Kandeler <christian.kandeler@digia.com>
Bump version.

To 1.3.3.

Change-Id: I6d3fa52de7a2682fa3bc93ecf8c37121c5b19233
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
License update.

Add LGPLv3 option.

Change-Id: I8a63ad5e46a2701032b2103f791df4dec5b707e8
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
Set the initial value for "destinationDirectory" to "buildDirectory".

In BuiltinDeclarations. The replacement we do in ProjectResolver could
be too late for some contexts.

Change-Id: If418f894fd8d161399b25a03e56876b34c3ee1cc
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
complete license header update

Change-Id: I2c7ea3242e5ce244e8feee01c0f8a0b0651fa0d4
Reviewed-by: Christian Kandeler <christian.kandeler@digia.com>
Merge remote-tracking branch 'origin/1.3'

Conflicts:
    qbs_version.pri
    version.js

Change-Id: I645b2f37bae9d36d4bca54b267d57df8b0b7fd21