print/merge document issues

ref CRM-17608

there are a few issues with the new merge to docx/odt functionality. these are low priority, but we want to keep track of the issues anyway:

1. there appears to be a conflict with the spell-checker in Word and tokens. if you create a Word doc to use as a template and insert tokens, they will be flagged by Word as a spelling error. when generating a merge from that file, the token will not be processed. if you tell Word to ignore the spelling error, the token is processed correctly.
2. if generating content on screen, html tables are not generated in Word/ODT docs. the entire block of content contained in the table is completely missing. it does generate properly for PDF.
3. it would be good to do more testing to see if the generator library we are using provides better handling of html entities. for example – I noticed that header tabs (e.g. <h2>) have no distinctive styling applied in the Word doc.
4. no activity records are generated upon merge. previously, Civi would create an activity record when you merged to PDF. I believe part of the intent of the "Preview" button vs. the "Download Document" button is to distinguish between a test (which should not have an activity record generated) and the "actual" download, which would have a record created.
5. if you create a message template using an uploaded Word file, when applying that template in the Print/Merge Document interface there is a preview displayed. it's pretty rough... in the testing I did, it barely passed as a "preview" – basically it displayed the text of the file, sometimes in pretty unreadable display. we should either look at improving that or perhaps just disable it altogether. I don't think it's current format provides much benefit.

of these issues, the activity record is probably the most significant, simply because it is a regression.