Make fig_t1_t2_agreement.png same as fig_t1_t2_agreement_per_vendor.png

[valosekj]

After changes in fig_t1_t2_agreement_per_vendor.png figure, I assume it would be nice to adjust fig_t1_t2_agreement.png to looks alike.

Possible improvements I noticed up to now:

• move grid to background
• increase title size
• adjust x- and y-axis limits to be dynamic (now they are fixed)
• decrease spacing between symbol and vendor name in legend
• change transparency of legend box (now grid is visible)
• change color of legend box's frame to black

[jcohenadad]

@valosekj given the strong overlap between this figure and the vendor-specific figure, i am wondering if we should keep maintaining it. For the article, i am thinking of only including the vendor-specific one.

[valosekj]

@jcohenadad okay. So I let this figure in current stage and we will know what to improve if we need it once.