add IntelliJ-IDE-generated overlay directories to .gitignore
add IntelliJ-IDE-generated overlay directories to .gitignore

IntelliJ IDE can helpfully generate directories reflecting the overlaid-upon `.war` files.
These directories should not be committed to source control (being generated from source) and this commit enhances `.gitignore` to help developers to properly ignore these directories in interacting with source control.

timlevett/uPortal,GIP-RECIA/esco-portail,apetro/uPortal,Jasig/uPortal,Jasig/uPortal-start,Mines-Albi/esup-uportal,joansmith/uPortal,GIP-RECIA/esup-uportal,MichaelVose2/uPortal,chasegawa/uPortal,chasegawa/uPortal,kole9273/uPortal,jonathanmtran/uPortal,vbonamy/esup-uportal,EdiaEducationTechnology/uPortal,groybal/uPortal,ASU-Capstone/uPortal-Forked,jl1955/uPortal5,doodelicious/uPortal,vertein/uPortal,cousquer/uPortal,vertein/uPortal,vbonamy/esup-uportal,groybal/uPortal,andrewstuart/uPortal,jl1955/uPortal5,GIP-RECIA/esup-uportal,stalele/uPortal,ASU-Capstone/uPortal-Forked,timlevett/uPortal,jameswennmacher/uPortal,joansmith/uPortal,kole9273/uPortal,chasegawa/uPortal,jl1955/uPortal5,doodelicious/uPortal,Jasig/uPortal-start,cousquer/uPortal,joansmith/uPortal,bjagg/uPortal,Jasig/uPortal,stalele/uPortal,GIP-RECIA/esup-uportal,chasegawa/uPortal,phillips1021/uPortal,GIP-RECIA/esup-uportal,timlevett/uPortal,ChristianMurphy/uPortal,doodelicious/uPortal,groybal/uPortal,apetro/uPortal,phillips1021/uPortal,ASU-Capstone/uPortal,GIP-RECIA/esco-portail,doodelicious/uPortal,Jasig/uPortal,GIP-RECIA/esup-uportal,EdiaEducationTechnology/uPortal,doodelicious/uPortal,joansmith/uPortal,bjagg/uPortal,vbonamy/esup-uportal,jhelmer-unicon/uPortal,vertein/uPortal,ASU-Capstone/uPortal-Forked,ASU-Capstone/uPortal-Forked,jhelmer-unicon/uPortal,jhelmer-unicon/uPortal,bjagg/uPortal,ChristianMurphy/uPortal,jonathanmtran/uPortal,kole9273/uPortal,stalele/uPortal,jameswennmacher/uPortal,MichaelVose2/uPortal,phillips1021/uPortal,phillips1021/uPortal,jl1955/uPortal5,stalele/uPortal,jameswennmacher/uPortal,jhelmer-unicon/uPortal,MichaelVose2/uPortal,mgillian/uPortal,Mines-Albi/esup-uportal,andrewstuart/uPortal,kole9273/uPortal,EdiaEducationTechnology/uPortal,cousquer/uPortal,groybal/uPortal,jhelmer-unicon/uPortal,apetro/uPortal,jonathanmtran/uPortal,phillips1021/uPortal,jameswennmacher/uPortal,chasegawa/uPortal,joansmith/uPortal,mgillian/uPortal,stalele/uPortal,Mines-Albi/esup-uportal,vbonamy/esup-uportal,ASU-Capstone/uPortal,ASU-Capstone/uPortal,MichaelVose2/uPortal,andrewstuart/uPortal,GIP-RECIA/esco-portail,ASU-Capstone/uPortal,ASU-Capstone/uPortal-Forked,jameswennmacher/uPortal,apetro/uPortal,andrewstuart/uPortal,Mines-Albi/esup-uportal,jl1955/uPortal5,Mines-Albi/esup-uportal,EdiaEducationTechnology/uPortal,timlevett/uPortal,kole9273/uPortal,ASU-Capstone/uPortal,vertein/uPortal,andrewstuart/uPortal,vbonamy/esup-uportal,groybal/uPortal,apetro/uPortal,MichaelVose2/uPortal,ChristianMurphy/uPortal,mgillian/uPortal