Upgrade tcpdf to 6.0.077

6.0.077 (2014-05-06)
	- A Datamatrix barcode bug was fixed.

6.0.076 (2014-05-06)
	- A bug in Datamatrix Base256 encoding was fixed.
	- Merged fix for SVG use/clip-gradient.
	- Now it is possible to prefix a page number in Link methods with the * character to avoid been changed when adding/deleting/moving pages (see example_045.php).

6.0.075 (2014-05-05)
	- Bug #917 "Using realtive Units like ex or em for images distort output in HTML mode" was fixed.

6.0.074 (2014-05-03)
	- Part of Bug #917 "Using realtive Units like ex or em for images distort output in HTML mode" was fixed.
	- Bug #915 "Problem with SVG Image using Radial Gradients" was fixed.

6.0.073 (2014-04-29)
	- Bug #913 "Possible bug with line-height" was fixed.
	- Bug #914 "MultiCell and FitCell" was fixed.
	- Bug #915 "Problem with SVG Image using Radial Gradients" was fixed.

6.0.072 (2014-04-27)
	- Deprecated curly braces substring syntax was replaced with square braces.

6.0.071 (2014-04-25)
	- Bug #911 "error with buffered png pics" was fixed.

6.0.070 (2014-04-24)
	- Bug #910 "An SVG image is being cut off (with clipping mask) when you use align options" was fixed.

6.0.069 (2014-04-24)
	- Datamatrix Base256 encoding was fixed.

6.0.068 (2014-04-22)
	- Some Datamatrix barcode bugs were fixed.

6.0.067 (2014-04-21)
	- startLayer() method signature was changed to include a new "lock" parameter.

6.0.066 (2014-04-20)
	- Bug #908 "Linebreak is not considered when getting length of the next string" was fixed.

6.0.065 (2014-04-10)
	- Bug #905 "RGB percentage color bug in convertHTMLColorToDec()" was fixed.

6.0.064 (2014-04-07)
	- Header and Footer fonts are now set by default.
	- Bug #904 "PDF corrupted" was fixed.

6.0.063 (2014-04-03)
	- Method TCPDF_IMAGES::_parsepng() was fixed to support transparency in Indexed images.

Signed-off-by: Michal Čihař <michal@cihar.com>