Reduce nesting / style in thumbnail creation routines

Change-Id: I733b677f4d4c7dfdf6fef531b43e1de36131f55d
sanitize "using" and "using namespace" declarations

Change-Id: I0b0cccc2d9cfe721c1ed421e614c4350a6b3dc7c
drawingml: Use SVX_NUM_NUMBER_NONE as default numbering type

Change-Id: I159fcf41fdb6c49687004e959d4032aef28678a5
reduce nesting in WriteParagraphNumbering

Change-Id: I49a3c3449d8354ce5e2a6e42414fbefdfc489388
parseXml should return xmlDocPtr instead of htmlDocPtr

Change-Id: Ia9fb79ea40ca840d7328a078e747ad64a63d18f1
drawingml: remove AUTONUM macro, unneded checks

Change-Id: Ie0ad7ed9df9d0d1b19fa09b3a4b93a5cbd6b41c6
bnc#822347: Test for bullet character defined as '' - empty char.

Change-Id: Ie771a5e53f04c0cd307d24a8bfc3ab7bc9a3094a
bnc#822347: if number type is not set, skip numbering

If numbering is detected then (level is > 0) and the number type
is not set, the defult bullet symbol is written. This is not
correct as the default should be SVX_NUM_NUMBER_NONE which should
skip numbering or set it to none. With this change the numbering
is skipped (as in MSO).

Change-Id: I8d08a6325509c7bd6f96f64c8d29e5f3045458ca