vim-patch:7.4.434

Problem:    gettabvar() is not consistent with getwinvar() and getbufvar().
Solution:   Return a dict with all variables when the varname is empty.
	    (Yasuhiro Matsumoto)

https://code.google.com/p/vim/source/detail?r=v7-4-434
vim-patch:7.4.442

Problem:    Using unitinialized variable.
Solution:   Pass the first window of the tabpage.

https://code.google.com/p/vim/source/detail?r=v7-4-442
Merge pull request #1704 from fwalch/vim-7.4.434

vim-patch:7.4.434, vim-patch:7.4.442