Batch #4

[vovanmix]

1. make .branch-name color whitish

.branch-name {
    color: rgba(27,31,35,0.6);
}

2. make this text color like link color:

.access-token .token-description

3. codemirror broke:

.cm-s-github-light .CodeMirror-lines

4. .branch-name on a label in newsfeed is too dark

5. .review-summary-form-wrapper (writing review panel) has a white BG

6. md text in diff is too dark:

.pl-mi {
    font-style: italic;
    color: #24292e;
}