Displaying Talk Speaker only if we have the info

refs #110
Merge pull request #112 from oncletom/speaker

Displaying Talk Speaker only if we have the info
Adding block quote basic styles, fixes #116

Feel free to design something sexier
Merge remote-tracking branch 'goulvench/master' into blockquote
Add some basic blockquote styling
Merge pull request #118 from DirtyF/blockquote

Blockquote basic styling
add some basic styles for tables
Merge pull request #120 from DirtyF/table-styles

add some basic styles for tables
Avoid titles linking to the current page
108-speaker-and-talk-language-attribute
119-sponsor-page-enhancement
Merge pull request #121 from goulvench/104-avoid-self-linking-titles

Avoid titles linking to the current page, fixes #104
115-spacing-news-list
Merge pull request #123 from goulvench/119-sponsor-page-enhancement

Removing absolute positioning for logos on sponsor page, fixes #119
Merge pull request #124 from goulvench/115-spacing-news-list

Adding a separator between news items, fixes #115
Fixing breakpoint mismatch for header img (between 480 and 600)
Merge pull request #125 from goulvench/breakpoint-mismatch-for-header-img

Fixing breakpoint mismatch for header img (between 480 and 600)
Replacing domain-specific links with install-relative ones
Limit the news to only one for now on the homepage
correct css syntax for post title's background opacity