Update cpplint to 1.5.2 or newer to fix Qt signal false positives

[zehnm]

Expected Behavior or Design

cpplint correctly handles Qt signal and slot definitions in header files and doesn't mark them as errors.

Current Behavior or Design

public slots: must be marked with // NOLINT to disable the false positive.

Possible Solution

Upgrade cpplint to 1.5.2.

Detailed Description and Additional Information

• Fix for false positive on QT's "public slots:" lines. cpplint/cpplint#99
• Avoid false positive warnings for QT signals and slots extended syntax. cpplint/cpplint#144