[header-bot] updated file headers

[indent-bot] standardised indentation

[indent-bot] standardised indentation

Merge pull request danieljprice#97 from jameswurster/master

(particle ID) bug fix to prevent reusing IDs

Merge pull request danieljprice#96 from jameswurster/master

Tracking particle IDs

(allocate) seg fault fixed when nneigh exceeds maxp_hard; neighbour l…

…ist now always has size equal to number of particles

[indent-bot] standardised indentation

Merge pull request danieljprice#92 from jameswurster/master

compiler warnings & build failure fixes

[header-bot] updated file headers

[author-bot] updated AUTHORS file